I dunno Mogrel just pick something that you like and use it as an avatar. Basically you can plug any interest you have into deviantart, sift through maybe five pages of sonic the hedgehog pornography, and find an honest to god amazing piece of artwork for your avatar.
Just really, really make an effort to pick something that does not make people immediately want to internet punch you in the dick, as is often the case with the avatars you choose I notice.
I mean I understand how ridiculous this must sound and how arbitrary avatars very much are, but the fact remains that at a glance, when I see you as one of those fucks from DBZ that constituted 90% of the filler it makes me not a happy camper. Not giving off this impression is an important thing.
It has to do with that messy web of associations folk have that determine that PIVOTAL immediate opinion/feeling you get on something.