i'm biased, but i'd say xbox. here's why:
-hdtv support (component outs via the high def pack)
-game support (although not quite on the "up and up", will emulate older systems)
-dvd/cd player
-digital out
-dts
-large media support (divx, mp3, wav, wma, avi, etc...)
-price ($130 used, $30-75 mod chip, hdd/dvd-rom upgrades optional)
-huge support base (
www.xbox-scene.com is a great source of info)
-imdb built into media player (xbmc)
-wireless remote (optional)
feel free to email me for more info