There was a program I used that ripped sound effects out of MAME roms. I can't remember the name of it, but you load the rom up in it, and then a huge number list came down and each one you pressed had a different sound effect or actual stage music. I remember doing a Bad Dudes cover and I was able to rip a crystal clear sample of "I'm bad!" and "Got it!", but I never used it because I couldn't get it to sound right in the cover. Let me do some detective work and see if I can't find it, because it'll do exactly what you want. It's not a repository, but, hell, it's easy enough that you can get whatever you want + make your own.