It is usually a horrible, soda like nonsense and it is usually found in name brand peanut butters these days. Stick with teddy brand or an organic brand. The organics taste a bazillion times better. It's like wow, I can taste the roasted peanuts, not the fake sugary spread.
If you do want the sweet, try wholefoods honey roasted peanut butter out of the automatic dispenser (makes it fresh on the spot in the store). Amazing.