My machine for the big screen is a tiny Zotac, running XBMC. The max it does is 720p, which is virtually 'retina' for a living room setting. Monster screens need full 1080p, but don't put them in a small room if you have old eyes like mine, and never sat in the very front of a movie theatre.
But my camera does 1080p, and so do the 'other sources'. In fact, I now only use 1080p for the 'others'. The latest thing is ultra-compression which puts these things under 2 gigs. I find that amazing. My little machine can't de-compress and downscale on the fly, so I pre-digest these things with Handbrake.
I use the Apple2 setting which is 720p. If you work from the high-res, I find it much better than using a direct 720p. The new compression must add highlights when working from higher resolution. The result is fantastic, and is probably the best I can ever get.