To date, my favorite connection between my computers & my HT has been an Xbox 360. I don't care much about internet content on my TV, or spreadsheets in my living room. The Xbox 360 does an OK job of displaying photos, and a great job playing music. You can make up on-the-fly playlists, and then display a hi-def light show on your tv.
My son (halo player) recently moved his Xbox from the living room/HT to his room. I'm thinking about buying my own 360, even though I most likely will never play a game on it, and just use it as a media device. If Net Flix offers rentals through it, I'll buy one the next day.