I've been using Ubuntu as my main system since 7.04 with a few short breaks using Windows or Fedora because of temporary hardware/software incompatibilities. I support FOSS projects like Ubuntu for a number of reasons but the biggest one is that the software works and it works well--often better than the non-free alternatives.

I'm no guru but in my travels I've learned a thing or two about using/debugging/fixing problems in Ubuntu which I'm always happy to share with the community. If it hadn't been for the help I've received from the Ubuntu community over the past few years I probably wouldn't have gotten past my first month of using it much less to where I am today!