I've been trying the new Ubuntu 8.04 for the last few days; I can say that this is the best Linux distribution thus far for desktops that I have used. Everything seems to work as it should and its damn good and stable.
If you are one of those guys; who tried Linux a few years and thought it was not ready for the desktop; then I strongly suggest you try this one. One of the key advantages is that you can even install it over your existing windows partition. Try it out; if you like it; get rid of Windows, I know a few who have already done so. :)