smelly towels

Along the same lines as clean smelling rooms and shower curtains, can somebody advise what they use to keep towels smelling nice?
No matter how few towels I wash together they always seem to get stinky after someone uses them and gets them damp. I've tried ammonia - it washed some color out of them, baking soda - didn't help, hydrogen peroxide - worked well but thats kind of expensive to put into every wash. I wash in hot water and dry them twice on hot in the dryer. We have well water if that matters.