I have just finished watching some movies I had put on my laptop for travel away. Sounds dull I hear you cry. Well yes it would be without the fact that I watched it on my tv via my xbox whilst working on laptop...
Rivet is the culprit.
It works fantastically well. No complaints, no problems. Easy setup, easy usage, literally drag and drop the movies you want to watch into the appropriate folder. True not all codecs are allowed, but frankly nearly all of them work - only matroska seems to be against the rules.
If you're thinking of an Apple TV and already have an Xbox 360, get it - only £20. Admittedly not for iTunes content yet, but hopefully we'll get around that soon.
9 out of 10 definitely.