The chipped disc issue has not been my personal experience. I've bought at least a dozen games from GF in the past year and they've all been fine (MY definition of fine - no major visible wear and is playable). I don't buy used from anywhere else now. Sorry for those who report a negative experience with GF games, but I don't seem to be able to understand because I have not had that experience in over 4 years of buying from them.
They have the best prices around, great service and (for me) incredible reliability. I will continue to buy tons of games from them.
I only post this so that those with no experience with GF have the full spectrum of opinion.
Probably best that those with "chipped disc sensitivity" stop buying used or just stop buying from GF altogether and leave their sales for the rest of us. You certainly shouldn't buy used games if you're a collector looking for a certain level of quality unless you can inspect the disc prior to purchase.