If you don't care about beauty, then any machine will do.
If you do care (you've got the rest of your room looking nice presumably so why should this be an exception), then there is one simple answer: the Mac Mini.
It has a DVI port that (using a DVI->HDMI cable) connects very easily to a TV. It has bluetooth, wifi, and several USB ports built in. It does have a fan, but it's silent all the time except for when it's doing something heavy duty. Regular use, or even watching HD movies on it, shouldn't have it produce any noise.
It's also got a DVD player, to play your films with, and comes with the Front Row interface (using a handy remote, or your iPod touch or iPhone), making it easy to use from the couch.
If you really don't want to run Mac OS X on it (I'm not sure why not), then it'll also capably run Windows too, including the Media Centre release.
If you live near an Apple store, check them out.