MAME/CPS Woes and Troubles

[Skulhedface]

Well, I just wanted a definitive answer, as it seems most other users around here have no problems.

If it is the ROMs themselves, is there another website that offers the complete downloads?

If it's the computer...well, I'm jolly well fucked.

If it's the emulator, well what's the best all-purpose emulator? That way, I can get some Alien Vs. Predator, Metal Slug, Rampage and Marvel Vs Capcom without frequent emulator changes...