Roll your own DVR and media center with MediaPortal
Lifehacker has a fairly high level overview with some nice screenshots of Media Portal. It's quite a powerful, and absolutely free Media Center application, so you should check it out if you're evaluating a system.
Aside from its core functionality, MediaPortal has a robust set of
installable plugins you can use to extend its functionality. For
example, there's Last.fm integration, Wikipedia integration, and an RSS Reader, not to mention a few games like Tetris and Sudoku.
Read the rest here .