Same here. I did have a Memorex Black CD-R (Prodisc) start skipping after about 2 years of it cooking in the car (and many many plays). I don't think it had too may scratches, but we have some pretty sizzling summers and the inside of the cars can get very hot, and with the disc being black, it makes it worse. It was never in a case, just go thrown around, or stayed in the player. Can't blame the disc, it did serve me well.
(Luckily I have the .c2d of the file so I burn the disc as needed)
As far as DVD's, I have a couple of G05's from years back that were given to me that still pass TRT's perfectly.
But after joining tis forum, I still look to get the best media.