I think an awesome avatar is something from people who love themselves, put unique items they have together. It's an art, other people may like it, others will not. But all it matters most is that the creator loves the avatar put it on show. At the end if ourselves think our avatars is awesome. Then it's awesome for us. Other people sayings whatever-else are just opinions afterall
I find avies that color coordinate really well (Simple avies or cluttered) or have a theme to them tend to be really nice avies.
I'm more fond of organized cluttered avies though. So much detail and yet still the colors blend nicely and at times give the avie almost a texture. <3
I used to like to find one item with a really strange or unique color, and try to build a matching avatar off of that, but now I tend more towards having a story (Even if I'm the only one who knows what the story is lol) behind an avi before I make it.
as far as other people's avatars...my favorites are usually people that match amazingly, or have a really strange/creepy style. emotion_awesome