If you're serious about gaming, get a less expensive Mac and buy a PC instead. Chances are, you don't really need all that power for non-gaming needs. Certainly there are exceptions... Greg probably will be running some high-end audio applications that deserve the computational muscle he shelled out for. But most of you chumps don't do much of anything that requires a powerful CPU with your computer if you're not gaming, I can guarantee that.
Personally, i usually go for a higher end model because they have a much longer usable life. I paid myself sick getting a maxed out PB G3 300 some five-six years ago, and until two weeks ago it was my primary computer that ran the latest MacOS well enough for daily use (and well enough to play games like Civ III and Europa Universalis II). Over five years, the initial investment isn't so bad compared to buying lower end models and having to upgrade once a year or two years.
That more than the gaming performance was the reason i went for an almost maxed out 15" PB G4 (almost because i've 'only' got 1GB instead of 2GB RAM
Also, Windowx XP is completely incorrect. Windows XP is utter crap. PC hardware, on the other hand, is excellent.
Oh, that i agree with. XP is a piece of sh!te that i unfortunately will have to work with when i go back to work, whereas if you know what to look for you can find some excellent hardware.