Bootcamp = Real Windows
I think someone should point out that when you use bootcamp, you are actually booting into Windows, just as you would on any other Intel-based PC. So even though you're on Apple hardware, you're completely Windows. No different from your current machine (of course, the hardware is newer and better). So if at any time a Mac alternative doesn't fit the bill for you, you can always go back to pure Windows.
Your best bet is using Parallels or VMware for convenience.
I haven't used Parallels for gaming, but I have used it for Zbrush 3, which is pretty graphics intensive (3D modeling in billions of polygons).
With Parallels (and probably VMware) you can run all your windows apps in coherence mode, which will have Windows windows floating right along Mac windows. It's pretty neat.
One thing that is extra cool is, if you hook up a second monitor, you can have one monitor as your Mac and the other monitor as your PC. But I prefer Macs so I use coherence mode usually.
Hope that helps