Community

Obviously adventure enjoyability varies greatly with the GM and Players at the table, not to mention what specifically you look for, and while most of this stuff has been said I feel I'll chime in, having done all the current 1-4s and 4-7s:

1-4s:
AGLA 1-1, Lost Temple of the Fey Gods- just plain solid in all areas.
CORE 1-2, Radiant Vessel if Thesk- ending is hilarious, and Jonster Yate is my hero.
CORE 1-3, Sense of Wonder- just good in all areas, and *gasp* a well thought out puzzle.
BALD 1-1, Flames of Initiation- I know lots of little tasks aren't everyone's favorite, but I always like things that assist immersing people in the setting, and I felt this adventure (and to a lesser extent, BALD 1-2) did a great job of that. Plus it's nice when adventures don't feel like deus ex machina.

4-7s:
CORM 1-2: Gangs of Wheloon nothing to say that hasn't been said in this thread, except that it's amusing to see players at the table snapping in time.
CORE 1-4: Crystal Clear- just very well thought out, immersive, challenging, and highly adaptable to GM/Player style preferences. Personally, I like adventures that give you more information than box text and encounter information.

7-10s: (I've only played a few, but...)
IMPI 1-3: If you're looking for a challenging adventure, look no further....and remember the death charity clause is really nice. :-) Avoid if you don't like highly difficult combat encounters. I enjoyed it immensely though. There are other good things to say as well but I don't want to spoil anything.
CORM 1-3: Very fun, and as usual, you can do it in many different ways. I think the Cormyr writers deserve some cookies.

Can't Miss Regions:
Cormyr
Dalelands
Baldur's Gate
Core (I know that's just the misc. category but they have all been great IMO.)

There are of course other great adventures and regions but I will only blather on so much....

Ideally, people can read this thread and notice large trends.....