Thought i'll leave my comment on this as well.
in 1 word to answer ur question...uniqueness (if that's a word that is lol)
Personally i have a thing for realism, meaning more real life like shapes i.e. u don;t see every single person on the street a next top model just popping off the catwalk to buy some milk in local superstore in rl do u.
Again it;s a personal taste and one can;t really judge others for the choice of their avs, but when majority of ppl have similar body frame it kinda gets tiring and mono-tone. Isn't SL suppose to be a creative place, and with almost every1 looking slim fit it;s hardly being creative and expressive.
Here's a variation of my av i use.
How sad that some idiots out there think that this only can be a fancy dress for a party...
ps: is artistic nudity allowed on this forum?