If you buy a mac and install windows that kind of defeats the purpose.
Disagree. Dual-booting so you have both OS's on your machine and can choose is ridiculously easy and gives you the best of both worlds. There are also tons of options to run the two OS's literally simultaneously on your Mac box, now that they're intel machines.
That said, I'm not really suggesting you buy a mac to install windows on. I'm saying even if for whatever reason you start regretting buying a mac and wishing you'd bought a windows box, it's as simple as installing windows, so in that sense buying a Mac is basically risk-free.

Imac
*twitch* Few things in life tilt me more than this.