Best way to fix damaged games

 Hey guys do any of you have any advice on how to fix damaged games? Should I buy a disc doctor or is there something I can use to buff it out? I have a couple of games that you can't even tell are scratched but become unreadable during certain parts of the campaign. Also my 360 fell over because of the shitty non breakaway recharge cable (tripped over it) and my copy of WAW now has a ring around it making me not be able to play some campaign levels and a couple of multi-player maps. What do you guys do when this happens?
 
I was thinking of renting the games I have and swapping the disc and letting the store deal with it but that's kind of an asshole thing to do.

This is gonna sound weird, but if you run the disk under warm water for a few seconds it might work.  I do this with CDs that skip and they work fun afterward

wrap it in a towel.

I heard cleaning it gently with a cloth with a tiny drop of washing up liquid works quite well.

White chalky toothpaste on scratch and rinse it off with warm water.

" White chalky toothpaste on scratch and rinse it off with warm water. "

A light coating of mineral oil should help small scratches.

Just use a hammer and nails and do it the man way.      :P

Yer lucky man, before i learned to nail down my 360 i knocked the console over, not only destroying Bioshock but also my xbox' lens, thus rendering it a write off. 
 
May sound retarded but a tiny bit of butter spread over the scratches helps alot as butter = oil but thicker

" Just use a hammer and nails and do it the man way.      :P "