Matthew's common rooms were usually pretty nasty and empty when I lived there two years ago, but it is an option.
I had a neighbour in first year who brought a flat screen and hung it up above his desk in such a way that it didn't get in the way of anything else. If you can pull that off, then yeah, I'd say its worth it. He watched a bunch of movies in there and invited people all the time, all in the comforts of his own room
Or you could do what my roommate did and get an extra computer monitor (maybe 19') to hook up to your laptop. That way, you can go dual-screen (which is actually really useful for assignments and watching videos - I've adopted his method and went dual screen for all of second year
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