If you have some beautiful old pots and pans that you just can't get clean (and wanting to stay frugal - you want to save them!) then try Barkeeper's Friend. At the store where I work, we sell a few bottles of it everyday, and it literally gets most types of pots and pans gleaming clean again. It's available in both a powdered form and in a paste.
It's also a great way to 'deep clean' your stainless steel sink once in a while, because it's stunning how good a job it does.