The MAME guys cracked Capcom’s CPS III encryption about a week ago and have made a startling amount of progress since then. (In fact, I just grabbed a bunch of CPS III dumps from Usenet in preparation for the moment when a Mac OS X port is released.) CPS III was the hardware that all 600 versions of Street Fighter III ran on but wasn’t compatible with the MAME emulator until last week. You’ll find no ROM links here, but when the CPS III-compatible MAME hits, you can bet I’ll be taking a sick day. Sorry, John.
And who knows, maybe someone will resurrect the Xbox 1 MAME port now.