@Goldenzeal @Kaarme @wilddeath
It depends for me. For beef related foods, I prefer ketchup or BBQ sauce.
For chicken related foods, I prefer mustard or melted cheese (esp. salsa con queso). Something with a small kick.
Pork and lamb, I actually prefer to not put anything on it.
Fish as well, either nothing or sweet n' sour sauce. my family puts ketchup on fish, but to me it kills the taste.