Oh well, accidents happen. That stuff used to bug me so much also, but I just tell myself it's all going to perish one day anyway. Might as well not lose sleep over it. Still, the OCD side of me knows it's there....
If I'm responsible for the damage (I have dropped a few cases or accidentally leaned on them) then I accept the fact and try to be more careful. When they come from the store that way it's a bit more bothersome. Especially when you know it was somebody on the other end that shouldn't have packaged it that way. One time I got a CD that had the booklet creased and rumpled so badly I had a hard time pulling it out of the case.
It also bugs me the way other people treat their things. I don't put so much as a fingerprint on any of my discs, but the few I've lent out over the years have all come back (well, one didn't even make it back) with some type of permanent marking. I'm admittedly a neat freak, but I honestly don't know what people do to put this type of wear on their stuff. You take the disc out, you put the case on a shelf or table or the top of your TV, or at least a part of the floor out of the way of foot traffic. How hard is that? And where is the dirt coming from? Unless you have dogs or live in a tepee I don't know how to explain all that grime. Maybe I don't want to know. Couch crevices aren't the best places to store things, and neither is the floor of your car. Also, the trash can is where garbage goes, not those aforementioned places. Reminds me of that Friends episode where Ross ends up in a woman's apartment filled with crap and there's something moving underneath all the crap.
It's not so much the state of my material possessions that concerns me but the lack of respect some people show. They're just too lazy to care. Anyway, if you really want to damage a CD, the most fun way is, of course, the microwave.