In my very recent experience between Virtual PC, VMWare, and VirtualBox:
If you want 3D Graphics Acceleration: VMWare. Program seems to fail DirectX check immediately on the other two (full disclosure: yes it was a game ;).
Otherwise some Google querying with the underutilized wildcard can yield some quick comparisons, e.g.: "virtualbox * faster OR performance * virtual pc" (and then reverse the order, substitute names, etc.) repeated for whichever quality you wish.
I'm personally very satisfied with VirtualBox and its performance, but needs vary.
(Hopefully that wasn't too much of a subjective slide from "list some" to "compare some".)