Fedora 6 w/ Windows XP Shell. Reason, it doesnt need a microcrap OS to run. Linux allows me to code programs easier. Oh and yes I do use this for gaming =] got to love it.

xp, iam not a big enough nerd to know how to use anything else.

Ubuntu is actually pretty easy to use.

I gave my old computer to my mother (which convienently =already= had linux on it) and she seems to surf the net and check her email quite easily.

When I come and visit her house again, I'll teach her how to print and transfer photos from a digital camera. She doesn't know how to do that on Windows anyways, so eventually she'll just come to know only linux

I used to run Windows Vista, but then switched back to Windows XP :) Windows Vista does have a cool disk partition program though, but other than that, I think XP is better.

I used to run Ubuntu but am now on Debian Etch. I'm not too technical so I just install what my tech support (partner) tells me to. I used to run windows on one of my laptops but had quite a few freeze ups and crashes.
I like Debian (& Ubuntu) for many of the reason Game_boy said. They just work. If I don't have something there's a cool package managers that will download and install updates. I wanted to re-do my CV so downloaded OpenOffice in minutes. I wanted to watch videos so just told it to get VLC player. Easily installed and worked with no hassles. A quick package download and my laptop can now play any DVD from any region. Best of all Microsoft doesn't get any of my money.
I admit that it does require someone techie to show you the ropes initially.

XP and Gentoo. Ran Ubuntu for a while, missed portage, now back. Run XP because school network gets pissed off with Gentoo.

I run Mac OS X as my main system on my Macbook Pro. I have another mac aswell running Mac OS X and a pc running Windows XP pro.

As I said, I run Linux on my web server and have been running it for years.  I am not a n00b who needs time to adapt to Linux.  I tried Ubuntu for several hours, not 15 minutes.  Software would not install properly with the package manager, it would not install properly from the command line, and it would not install properly after reading several FAQs and HOWTOs and fiddling with all the configuration files.  All I wanted to do was install Eclipse so I could do my Java development for a class I was taking.  I had it up and running in Vista in no time flat.

I use Windows because it allows me to use my computers without fiddling a lot with drivers, configuration issues, and etc. Besides, I can find applications for doing anything with it, and whenever I feel like using unix style shells and utilities, cygwin to the rescue!

PS: Different versions of Windows I currently use include 2000, 2003, Vista...

 You've been able to avoid driver problems with 2003 and Vista?! What is your secret?