I've always been drawn to the bad side, too! Seems like the Villain attitude can be a hit or miss, I've heard lots of stories where little kids have been frightened, but throwing down somebody's possessions is pretty suckey. Depending on how humorously it's done, I think it can actually be pretty humiliating to have to retrieve your own autograph book/softball, and then if you really want it, return to ask AGAIN for an autograph??? I would've left, too.
My good experiences, on the other hand, have been with the Queen of Hearts, who singled me out during spectromagic, and then shook her finger at me and motioned the "off with your head!" It was great, especially since "Alice in Wonderland" is one of my all time faves!