there was a PS1 emulator called Bleem! which worked 100%
the company closed down, i think got took over by another company which ships the famous Connectix Virtual Game Station (CVGS) which is now owned my Microsoft.
perhaps they didn't want this company making an Xbox emulator since connectix makes alot of virtual machine/emulator software.
there isn't a stable version for PS2 emulator yet, unless its from a reliable source most likely its a virus/trojan, same goes for xbox emulators.
more info and tools below ;)
http://www.aldostools.com/psxemus.html