I like some avs, and naturally am attracted to the posters behind the good ones, unless they turn out to be total wanklettes. Some avs are scary, antagonistic, or weird, and I distrust the poster. Some avs are boring, and the poster usually is, too. Then some posters change their avs all the time (like Stroller -- bring back the fekin kitty, you binker) as if they got a personality disorder. I like to scan and when I see an av I know, I can immediately identify if it's friend, foe or nobody.
And then, there are the flash or motorised avs that are silly (except for Spin's; I think his is great).