You'de be amazed at some of the stuff out there for free.
I run Linux on my latop whenever I can. I rarely boot into windows - i only use windows for MTM2 and a few other things.
If u want to give one a try I suggest Suse Linux. But i'd say u should try it on a fresh computer - dont try to dual boot windows and linux on a machine that's important to you until you are somewhat familiar with the installation process.
To try linux on a machine without installing try Knoppix. It just boots off one CD.
http://www.knoppix.org/