I currently have 2 ways to play MVC2.
First on Xbox with Coinops 4 as the emulator.
I also have a separate DC cabinet setup just for Soul Calibur and MVC2.
Technically, neither of these are emulators since they run on actual hardware.
...but by using a cabinet, I am "emulating" the arcade versions and both run perfectly.
I guess this won't help you on a PC tho.
I doubt PS2 emulation would run as well, but have never tried it.