Check out the freshly released Fedora 10 Linux distrobution at http://www.fedoraproject.org
I can genuinely say after using Fedora for just about a year now the community is extremely supportive, and it's a very solid OS (Operating System). I can't see myself honestly moving back to windows ever again other than to give clients a desk top. I think if I was forced to switch I would use the Mac OS which is BSD based. What this means is that most of the best rated operating systems are built around the original Unix distrobution when computers first came out.
Microsoft continually tries to rebuild the wheel by cramming new forced features in but they run all the time so it takes the efficiency of the system down tremendously. The problem with Windows is that it is not as customizable as the add on parts, and simple check mark compilations such of linux distrobutions like Fedora. Seriously folks once you've tried Fedora you'll never want to use anything else. It might take a little learning curve at first but you'll never have to worry about viruses again. Your computer will run lightning fast, and you'll suddenly have twice the resources to do variable tasks.
I can genuinely say that it's been well over a month, and a half since I last restarted my desktop computer with it still running amazingly well. How many Microsoft Windows users do you know of that can say that? Since I started running this OS my career has excelled, and I have enjoyed many learning experiences that I would not otherwise have.
An OS should improve software not slow it down...