Loot is nice; satisfaction is better. 'Course, if you hate your party, or if you pull a triple-cross, you can sell them out for loot AND feel joy. But there's nothing quite like being the berzerking half-orc combat medic who charges in to gib kobolds & toss Cure spells around until THE DAY IS SAVED. (If you read that last bit in a certain narrator's voice, then I must be doing something right!)