If I had to pick one role to always play, it'd be one of the background members of the party, the one that sets up the other characters to do awesome things while looking relatively mundane and unintimidating. The plucky halfling that trips up and befuddles enemies so the others can knock them out, the wacky illusionist using his magic to protect his allies and confuse his enemies, the general's tactical adviser that knows all the ins-and-outs of battle but isn't a powerful warrior or mage, the alchemist, the engineer - all these characters are the sorts I like to play a lot.

(I don't like healers, however, but that's because I like my fantasy rife with danger and the threat of death.)

My runner up is the "Old warrior" archetype. You know: the one that isn't as spry as they once were, but knows more about war than everyone else? I like to play them as pragmatists and in as mundane a fashion as possible, wielding little to no great magics and certainly not being the best fighter in the company. However, this character makes a great tutor, or can give great advice between battles, and this character knows more about the true cost of war and the horrors it holds than anyone else in the fellowship.

I don't really like playing badasses to put it flatly.