Forget gaming in a virtual system. performance will be pathetic, you will have NO access to true hardware 3D acceleration, possible simulated 3D support in the near future. you would be better off with a Multiboot PC runnig Windows and whatever Linux/BSD/other you prefer.
Or look into Linux gaming, there are a LOT of native games on Linux these days, and commercial games with Linux ports. (search these forums for lists of games in Linux), and Cedega
will allow you to run a lot of Windows Games on a Linux system.
for your final question.. NONE OF THE ABOVE