I use Mac's personally, and somewhat professionally (my Macbook Pro serves as my mobile work computer as well using VPN, RDP, and various Open Source apps that I can use to connect to my work/client databases).
In the office I use a Win7 box, as is required. I have Win7 on my Mac Pro only for games. And then it's only for three (MW3, BF3, and as of today, Skyrim). If those games had Mac OS ports, I'd never use Windows on my personal machines ever again.
I never understood why tech people take the stance of "Oh you can't customize Mac OS as much as Windows, you can't put any hardware you want in it". That seems like a very small minority, at least at in my circle.
CAN I spend 5 hours hunting down a Windows driver issue or rebuilding my hardware from scratch? Yes. Do I WANT to spend time doing that? No. That's why I own Mac's.