Right now we have a tiny okeetee corn snake that is just a little jerk. She gets so defensive if you stick your hand in there. She puffs up, rattles her little tail, says mean things about your mother, and strikes. She will hopefully grow out of it. The adult we have has the personality of Winnie the pooh, he just seems like a big goof.
Aside from that almost every snake I have owned has been pretty mellow, even my rainbow boas.