I absolutely love how ubiquitous these things have become. They're genuinely useful for a lot of different purposes but, to me personally, I like how eco they are. I realize this sounds a bit eco-hipster, but I really mean it: Whereas people used to have big media center machines under their TVs, you can just pop a Pi underneath your TV, install RaspBMC, and that's all you need. It takes 3-4w, nothing more. Lovely.

Having said that, a 60" TV and surround sound receiver will probably also take a least a few watts, if I had to guesstimate :)