This exercise is in optimizing damage on charges. This is with a barbarian, of course, since barbarians get a free charge attack or two per combat. The build is quite playable from 1st through 30th, and offers both high DPR and very good combat control.
Model LT - Warforged Barbarian (multiclass fighter) / Warforged Juggernaut / Demigod or Chosen
Starting Stats: Str 18, Dex 14, Con 16, Wis 13
Ending Stats: Str 28, Dex 24, Con 18, Wis 15
There's a lot of ways of optimizing a charge. You can mix and match based on your personal preferences, so I'll just sort them by tier.
Howling Strike (Barbarian at-will that deals +1d6 damage, and can be used on a charge attack, increases to +2d6 at 11th and 2[W]+3d6 at 21st)
Vanguard Weapon (+1d8 to charge damage, and a daily party buff)
Lancing Gloves (+2 to damage while mounted, later replaced by better gloves)
Powerful Charge (+2 to charge damage)
Horned Helm (+1d6/+2d6/+3d6 to charge damage)
Boots of Adept Charging (shift 1 after a charge)
Fast Runner (+2 to speed when charging or running - don't take if you will be mounted)
Mounted Combat (+5 to charge damage when on a warhorse, or +2d6 on a celestial charger - other mounts like elephants allow you to charge and have them attack at the same time. I prefer Obsidian Steeds, since they're portable.)
Greatspear Weapon Proficiency (+3 to hit / 1d10 weapon, weapon of choice for this build)
Power Attack (-2 to hit, +9 to damage - useful if we can push our +to-hit up high enough to only miss on a 1, which is actually pretty easy with this build)
Polearm Momentum (knock prone when pushing 2 or more)
Warforged Tactics (+1 to hit when an ally is adjacent to the opponent, which makes charging into the flank even better)
Weapon Focus (+1/+2/+3 to damage with greatspear)
Weapon Expertise (+1/+2/+3 to hit, in PHB2)
Battle Awareness (free attack on an opponent once per encounter, and opens up Surprising Charge, power swaps, and Warforged Juggernaut)
Fighter Power Swap Feats. Harrier's Ploy is incredibly good for a level 1 daily (shift 7 squares away from an opponent whenever he moves). Quicksilver stance is pretty good (though you'll have a similar stance through Juggernaut). The level 22 fighter utility Howl of Defiance that marks all targets in a close burst 5 and grants CA for the entire encounter is another exceptional option for this build. Rain of Blows, of course, is quite decent for a low level spear fighter, though barbarians get better powers by paragon.
Warforged Juggernaut (+1d6/+2d6 charge damage + push 1 and follow on a charge, among other benefits like +2 to speed and defenses when charging, ignoring difficult terrain, etc.)
If you don't want to be a Juggernaut (if you're not a warforged, especially), Shock Trooper is just as good (+Dex to damage on CA opponents), except it doesn't add a Push 1 to all charge attacks.
Thundergod Greatspear (+1d6/+2d6 charge damage). The +2d6 epic version is better than Vanguard weapon, but Vanguard has a semi-useful daily ability.
Spear Push (+1 push)
Frostcheese (Wintertouched + Lasting Frost frostcheese works just as well with a charger as anyone else, and is useful for getting CA for the next feat)
Surprising Charge (+1[W] damage when charging a surprised or CAed foe)
Fleet footed (+1 to speed). Don't need if you are using mounted combat
Mobile Warrior (shift 1 square after any attack with a spear)
Spear Mastery (19-20 crit)
Unstoppable Charge (your turn does not end after charging)
Seize the Moment, Secret Stride, Polearm Gamble, Pin Down, Improved Initiative, Dirty Fighting, Devastating Critical, Blood Thirst, Back to the Wall, Defensive Advantage, Defensive Mobility (for when not raging), Against the Odds, most of the Warforged feats, and others are all worthy options to substitute in.
For example, Pin Down can be game breaking by using the autoknockdown abilities of the barbarian combined with a grasping greatspear and the build's high fort and ref defenses. You charge a guy, push them one square, knock them prone, then action point grab them. They can't move and are stuck prone until they escape the grab. When in elite or solo combats, this is game-breaking. Especially, I've found, if you're holding the bad guy in the middle of a blade barrier. =)
The Model LT is built in Luskan, and trained in athletics, stealth, thievery, and perception. He actually makes a pretty decent substitute thief, but I just wanted him to be able to gain surprise on enemies to trigger surprising charge and then the frostcheese combo.
The powers you take don't especially matter beyond Howling Strike, since they're all pretty good. You'll have 3 rages per day, with the following options for rages: knocking an enemy prone at the start of your turn, +to speed, knocking an enemy prone on a hit (or adding +Con to damage), adding +Con to damage on bloodied enemies, adding +to hit for all bloodied enemies, adding +to hit for all enemies in sight, turning insubstantial when bloodied, etc. Lots of good options.
I outfitted the level 30 version of Model LT with the following items:
+6 Thundergod Greatspear
+6 Displacer Elderhide Armor (forces a reroll of all attacks on him, which helps cloak of invis last longer)
+6 Iron Armbands of Power (+6 to melee damage)
Rushing Cleats (+1 push) or Zephyr Boots (flying)
Gauntlets of Destruction (brutal 1 on all damage) or Frost Gauntlets (immobilize 1/encounter and +6 frost damage to all attacks)
Horned Helm (+3d6 charge damage)
+6 Cloak of Distortion (+5 to defenses against ranged attacks from 5+ squares away)
Shadow Band (concealment all day / daily: total concealment all encounter)
Star Opal Ring (+1 to speed / daily teleport 10) when not mounted
Ring of Ramming (+1 push) or War Ring (+1d12 on a critical)
Obsidian Steed / Warhorse (+5 to charge damage) or Celestial Charger (+2d6 charge damage) or Rhino or Elephant mount with Skystrider Horseshoes (fly 8 for mount) or Impenetrable Barding (Resist 30 on mount)
Frozen Whetsones (+6 frost damage, activates frostcheese without needing frost weapon)
Totemic Belt (daily: +1 to hit all encounter)
Charge Bonus to hit:
+3 weapon proficiency
+6 weapon enhancement bonus
+2 combat advantage
+1 Warforged Tactics
+3 Weapon Expertise
(And unlike a lot of builds on here, it will actually get CA, instead of pretending it will always get CA.)
If using dailies:
+Number of enemies in area (Untyped bonus; Rage of the Primal Beast - earlier you can add +Number of bloodied enemies in area with a lower level rage)
+1 Totemic Belt (power bonus)
+Number of bloodied enemies in area (Untyped bonus; Waxing Fortune from Chosen ED)
Depending on the number of opponents, this puts us high enough to only be missing on 1s, so we can use power attack:
-2 to hit
Final bonus to hit: +50 or so for a normal combat.
10 flying when on foot, 8 flying when mounted.
Charge Damage (all untyped unless noted):
2d10+3d6 Howling Strike (when raging, movement does not provoke OAs)
+6 weapon enhancement bonus
+1d10 Surprising Charge
+2d6 Warforged Juggernaut + Push 1
+3d6 Horned Helm
+2d6 thunder damage from Thundergod Weapon
+2d6 mounted on Celestial Charger
+1 totemic belt (power bonus)
+6 cold (whetstone or frost gauntlets)
+5 frost vulnerability (frostcheese)
+2 Powerful Charge
+3 Weapon Focus (feat bonus)
+9 Power Attack
+7.5 gauntlets of destruction (or +18 damage if you want to use bloodclaw spiked gauntlet cheese).
=3d10+12d6+54.5 cold and thunder damage, or 112 damage on a charge, 123.5 if you believe in using bloodclaw cheese. If we're using one of the rages that adds +Con to damage, increase the damage by +4.
The target is also pushed 4 squares and knocked prone. If Madden was announcing, he'd say, "Ooh! That was a big hit!" We can then shift one, and if all we have done so far in the round is charge, we can then move back 8 squares, and leave the target in a bad position: prone and 13 squares away.
It's great control. =)
Earlier on (11th level), you can do something similar by power swapping in Harrier's Ploy. When the enemy moves, you get to shift away 7 squares as a reaction. Then you can charge him again, push him and knock him prone, and then move away again. All combat long.
Crit damage (10% crit chance):
149 cold and thunder damage
+1d10 devastating critical
+1d12 war ring
=194 damage, or 212 with bloodclaw cheese.
Let's look at our DPR so far, since the CO boards seem unhealthily obsessed with this number (even though things like the automatic knockdown and escape, in practice, is MUCH more valuable than 10 DPR either way). Since bloodclaw cheese seems standard in DPR calculations, I'll use that number here: 5% miss chance + 10% crit chance + 85% normal hit chance = .1 * 212 + .85 * 123.5 = 126.175 DPR
Plus, we'll activate either Quicksilver Stance or the Warforged Juggernaut stance in most serious combats.
Quicksilver stance gives a bonus melee basic attack every round, and Juggernaut is the same, but no strength. Quicksilver stance deals 74 on a hit (128 on a crit), Juggernaut 48 damage per target, but no attack roll. Quicksilver is worth .10 * 128 + .85 * 74 = +75.7 DPR, Juggernaut a flat +48 DPR * the number of targets adjacent.
If he crits with an attack, he gets a bonus melee basic attack (74 damage / 128 crit) once per round. With two attacks at 10% crit rate, there's a 19% chance of picking up this bonus attack each round. This adds another .19 * 75.7 = +14.383 DPR.
Total DPR = 216.258 DPR using nothing but at-will attacks during a serious fight.
If you want to start throwing in situational factors, like Back to the Wall or Sigils of Companionship, it can inch up a bit higher, though I think it's pretty good as-is.
Note: this is all sustained damage, just counting on having a stance and a rage up during each serious fight (which he can do 3 and 2 times per day, respectively). Plus you get the fun of picking up a large handful of dice and throwing them on the table. Ever since 4ed turned fireball into a lame 3d6 spell, my cube of d6s has felt unloved.
The option of using a mount is an interesting one - dungeons are often not designed for mounts, but an Obsidian steed lets one sneak them in a lot of times, and a celestial charger with impenetrable barding or skyriders on adds a lot to a combat. Oddly enough, we can actually move faster on foot while charging, but being mounted has a number of advantages, such as our reach increasing from a 5x5 area to 6x6, and giving monsters the chance to waste their actions attacking a mount with Resist 30 All. Using a mount also frees up your foot slot if you put Skyriders on your horse.
You might note I didn't post any encounter powers. That's because no encounter powers are really relevant to the build (though there's a few that can be used while charging for a bit of extra damage and status ailments). Tailor them to your own preferences. There's also a lot of good choices in rages, which will depend on your tactical environment. Depending on how you pick your feats, you can probably take the warforged racial feats/powers, which are very good from a survivability standpoint.
He's not going to be nearly as fragile as most barbarians. AC 43, Fort 42, Ref 38, Will 34, but with displacer armor and a cloak of distortion, his defense is actually going to be a lot higher. Especially when you combine it with his control. Let's say he's fighting Orcus. Orcus is flying 15 squares up, so he charges him on his flying steed and knocks him out of the air and pushes him horizontally 4 squares and leaves him prone on the ground. He's out of the reach of Orcus's necrotic burst, and any ranged attacks that Orcus had that could reach him (which he doesn't) would be at -5 to hit from the cloak of distortion, and would have to be rolled twice due to the displacer armor. All encounter long. So Orcus is looking at about a 30% hit chance to hit Fort, and about a 50% chance to hit Ref, and, well, he'll hit Will. While this isn't incredibly impressive, it's a barbarian, which is the most fragile class in the game. The charge + push + retreat combination alone is enough to leave a monster prone and 15 squares away from the barbarian every round.
If you have your all-encounter total concealment ring running, then your defenses are +5 better. With Secret Stride (no penalty to moving in stealth), you could feasibly even avoid being targeted.
I've been playing a barbarian in LFR (not this build), so I've seen how barbarians work out in practice. A typical opening round for the Model LT would be to: fail initiative, let the rest of the party go on ahead and get ambushed, come in at the end of the order, charge a monster the other PCs have damaged, hit it for 100 damage or so, putting it down, taking a free action to shift and charge the enemy controller hovering in the back ground, critting him for 200 damage (and a free basic attack for 70 damage) and knocking him 4 squares away and prone, followed by a Spur the Cycle charge for another 100 damage and push 4, followed up by an action point charge into him AGAIN, hitting for another 100 and another push 4, and then spending a move action to shift and back away 11 squares out of his ability to do anything in retaliation. He ends his turn next to the party fighter, who has marked another monster. The monster attacks the fighter, Model LT makes a free melee basic attack in response (if the monster went after LT, the fighter would get a free attack - fun, huh?) and hitting that monster for another 70 damage. End of the round - no daily, or item powers activated, just an action point and a couple encounter abilities, and he's killed one guy, knocked the enemy controller prone and out of attack range on the party (and hit him four times in a round for about 500 damage!), and finished off by whacking a monster that was daring to go after the party tank.
If you have a spare Quick weapon and power swap in one of the fighter free action encounter attack powers, you could even get a couple more hits in if you felt like it.
That's how they roll. It's actually a pretty fun class to play. At the end of that round, you'd have rolled close to 100 dice. =)
If you don't want to charge, you can always use demigod loop cheese (at 30th) to attack with Hurricane of Blades each round. It works out to about 70 DPR per attack, with 6 attacks (and a 50% chance for a crit to grant a bonus 76 DPR, so another +38DPR there) and Quicksilver Stance for another 76DPR, for about 536 DPR sustained through the fight. It's certainly not bad, but 1) I dislike demigod loops and 2) Charging is more fun, and adds a lot more control to the battlefield.
To get you in the mood for playing him: