Smooth for me. Brand-indifferent, though I usually reach for Jif or Peter Pan out of tradition. Tried one of the local "all natural" offerings. Unimpressed, especially for the price.
Plain yeller musterd for hamburgers and hot dogs. No real preference, though French's seems to have the best balance. Brown and dijon for things like brats, strong cheeses, and certain recipes.
So glad no one has mentioned the heresy that is beans in chili.
Brad