I liked it when Qre:us had the bunny avatar. And I still associate MDP2525 with the Spongebob one, and BlueSprout with the spiders, lol
But my favorite current ones belong to:
Max (suits him well)
Jockthemotie (hilarious )
whatever (I Tintin)
The Outsider (a really well-made and interesting looking photo)
d@v3 (cute )
and, of course, my own
And current least favorite:
The one at the top of this page. Makes my eyes hurt
Magic Poriferan has the best avatar - hands down. It mesmerized me when I lurked here, and it still does. It has this endearing, 8-bit quality about it. It's almost gothic in nature, yet it's so uplifting. I can't place my finger on the special quality. Perhaps it's because of the duality of "happy-black". Yes. This is what it shall be dubbed.
In addition to the sleeping iguana smilies. Unspeakably awesome. Now I just sound patronizing, but it's true.
Also- Jaguar's. I know it's just an old Jaguar in a tree, but its stare has this happy/haughty nature to it. Quite amusing.