Mage or stealhty talky type. I don't like straight up fighters. If at all possible, I like to keep the amount of killing to a minimum. It's far more satisfying to sneak past all the guards, take a garrote wire to their leader, get the treasure, and get out before the front door guard gets done taking a piss in the bushes.
In MMOs, I love to play the healer. It's why I chose a druid in WoW, it gave me the option to access all three. My main alts are a paladin and a priest. Both healing specced.
I hate healers in single player though. At least you get some satisfaction occasionally from thankful players and you have the knowledge that the entire operation would have failed if you weren't there. I hate babysitting the lobotomized chimps that is the AI in singleplayer.