For my 10 cents, use Ubuntu. I recently switched to Ubuntu on my desktop after lots of attempts to give up my windows dependancy with different distros. Ubuntu gets my vote because it has a single disk install with everything you'd want by default, the debian apt-get system (which kicks RPMs ass) and a huge user community and documentation (like Empeg ) with lots of knowledge. The desktop is well polished too. Check out http://www.ubuntuguide.org as it has the HOWTO for any app class youd care to think of.

For me and my desktop, it is hands down the best distribution I have tried.