Go
here for a fair genisis emulator.
And go
here for a great gamegear emulator.
And get my attachment for a playstation emulator. Yes you heard that right. It supposedly works well with a nice overclocking tool.
You will need to rip the games from a REAL psx cd and then turn it to an iso file, you can seach google for that one.
This would be great for you raynne, you could do some final fantasy 7 rpg games. ;)