I have only played as a hero before, although being a villain sounds like it can be lots of fun. Provided I can pull it off.
Wherever your strengths lay lets roll with that. I am open to try out anything under the sun. I have yet to figure out where my RP likes and dislikes etc. lay. Only one way to find out if it is my new favorite food, try it!
Since I don't have any characters really thought up I'll name characters from books and movies that I really like to use as a template. These are in no particular order just first that come to mind.
Theon Greyjoy from A Song of Ice and Fire. This is probably my favorite character from the series. He tries to put off that he is the best, a man with no faults. This arrogance leads him down a path that he cannot come back. Deep down I think he just wants to have someone tell him "I'm proud of you." and he does everything, maybe even terrible things to make someone proud. He is arrogant, deep down he is insecure of himself.
Gollum/Smeagol from JRR Tolkien. I love Smeagol's story a whole lot. He is a innocent, child like soul, that gradually becomes so corrupted there is little to no chance of him being the innocent hobbit again. Like that whole idea of becoming corrupt with no hope of redemption. Also playing as someone with a split personality sounds like fun.
Vegeta from DBZ series. Entitled prince who believes he is the bees knees. Boy does he have something to learn.
Jake Sully from Avatar. Infiltrates the Na'vi with the intent of giving his commander the information he has learned. Slowly falls in love with the forest and the Na'vi and betrays his people for the good of the planet.
There are a few of the characters I really like.