At Work:
I use a Core2Duo box running FreeBSD 7.0 and a 180Mhz R5k SGI Indy Running IRIX.
At Home:
I have a Core2Duo box running FreeBSD 7.0 for routing/firewall/fileserver/desktop/etc and another Core2Duo running XP for Games.
Can't wait for the day that Wine can run all Direct X games well enough, I'd drop Windows in a flash