I mean, in terms of skill, probably Zoomo as well, but in terms of being a rad person, myself. Because I'm a kool kid.
I nominate @Pinelord! He has created some awesome sprites in a really short time. Of course I'm probably biased. I'll admit Zoomo has some friggin' awesome sprites though.
Have you guys never heard of @drain. ? I'd go for him, Zoomo, and potentially Eli. Can't remember any others.
Oh man... too many good spriters to pick from. I think the best of em though have already been mentioned.