Two words; dual boot
Two more words: Dual machines. Actually, triple machines if you throw in the Sun Ultra 5. Quad if you throw in the XP Home running laptop.
I have Linux (Fedora Core 4). I have Solaris 9. I have Windows XP. All three do the exact same thing, with the Windows machine only having the advantage in games. Other than that, I have no real preference. If I had to choose one, I like Solaris the best. But the box is old and slow, so I don't use it much.
I have never had any security issues on any of the machines, so it is a moot point.
Honestly, you could toss me any of them, and with the exception of gaming, I could be happy doing anything else. I frequently start writing code in Windows, and end up finishing up on the Sun or Linux box. I'll obviously test it on a couple OS's, and then on the CS department's Fedora machines, if for nothing else than to see any differences that may occur.
I know how to use all of my machines, I can use them all effectively. OS doesn't make much of a difference to me. I wouldn't go out and buy Vista, just like I didn't buy XP Pro (Academic license) or Home (came on the laptop), unless I couldn't run a game on XP. Just like I wouldn't buy Solaris (although licensing is free on their hardware), if Linux was free.
The only thing I don't really like is Macs. You wanna talk overpriced, start there. Especially when the OS is built on something that was free.
EDIT: Oh, and yeah, didn't mean to knock Tux Racers. I have played that game and lost track of time on numerous occasions. Excellently addicting game.