I love DnD particularly 3.0/3.5 due the the customizability.
I love playing the odd PC,.. the wererat, lich,... swarm of crawling claws,... hell I think it would be fun to play another PC's awakened animal companion. hey id even give a harry Krishna goblin a try.
I really badly want to play a Campaign in the Midnight setting from fantasy flight games, got a cool idea for a wild child character.