The Worst Adventure in the World

I think you ought to go with the rogue. He's a nice balance of offense and defense and shouldn't need as much support as the mage (who lacks defense) or "barbarian" (who lacks intelligence) - those two complement each other anyway. Also he can detect traps which sounds pretty dang useful.

He's also likely to ditch you at the first available opportunity, which may or may not be a good thing.