I run the following at least weekly, if not daily: Windows XP, Windows XP 64 bit, Windows 2003 enterprise, Window 2003 standard, Solaris 9, Solaris 10, Redhat Enterprise Linux 3, Redhat Enterprise Linux 4, Redhat Enterprise Linux 5, Centos 3, Centos 4, Centos 5.
I also occationaly use Max OS X (monthly maybe). I've installed Vista and used it a few times, but no real work...
Great thing about Linux, is what works on it, just works and keeps working. Rarely have to reboot, etc... It's hard to keep a windows system up for more than a couple of months, if for no other reason than critical patches will require a reboot.
I spend most of my time directly on XP and XP 64 bit, but remotely connected to Linux servers, and Windows servers. I still consider X windows severe bloat, and do most of my stuff at the command line in linux.
I don't feel like detailing 100 machines I use right now and why they run the OS they run, so let's just say I use whatever operating System is best for the job, or sometimes Windows anyways. You can get most games to work on Linux (especially with the commercial versions of wine), but it's a pain. Not much worse than getting some games to work on Vista though.








