Here is a great chart on the capabilities of Windows 7 Media Center, XBMC and Boxee. I personally use Windows Media Center which is part of Windows 7 and I really like it alot. WMC spotted my Hauppauge TV Tuner and green button remote without any extra device drivers. Setup was easy with Cox Cable. XBMC is nice also, but it doesn’t support a tuner. It does get meta data including TV, movie and music pictures, data about your media, reviews, and even trailer links for the videos and music. See the chart below and checkout Lifehacker for the full review.

Hulu has blocked Boxee from accessing their content, but you can use this plug-in to get around that.
XBMC has already put together a quick plug-in to bring Hulu back to both XBMC and Boxee. A Team developer called d4rk at XBMC has created a plug-in to the Hulu plug-in which does some fancy decrypting to get Hulu working on Boxee and XBMC.

Hulu Plugin for XBMC [XBMC Community Forums]
How To View Hulu In Boxee [Boxee Forum]