I really like high quality avatars that are like 6-12 seconds long. If they have cool visual effects and stuff like those Samantha Jade avatars from that one really nifty music video I'm forgetting the name of, that's a really big plus!
I also really like this avatar I currently have. :eyes:
Mostly male artist ones, depending on which certain music video pleased me. They're usually long ones, but reasonably. I like it to be random a bit. When I see 10+ members with the same pop girl avi's from the same music video scene, I get a bit confused at times.
I like pngs and as for avatars, as long as they don't have too much going on in them. I love them. Especially if they're HQ and colored right.
I hate stan avatars that have stats in them making fun of other artists and praising their faves. I also hate the sexual ones of shirtless guys or the ones where they're twerking and stuff like that. The ones like Jet's w/ the male models are okay.
It's really tacky to avi a music video as soon as it comes out (if it's by a popular artist) because the entire forum will be flooded with them. Also, avis that are supposed to be 'funny/trollin xD' or a meme are extremely annoying and lame. I usually like sharpened GIF avis, it could be from anything though.