Good summary, of course there are dozens more.
Still hard to top the R-Pi, with its impressive GPU and onboard video. Now they’ve introduced the Compute Module version: http://www.raspberrypi.org/raspberry-pi-compute-module-new-product/
We use Raspberry Pis with XBMC for our home theater, and we love them. I ripped my entire library of DVDs and BRDs to MKV and we can stream anything we want straight to the device with just a few clicks. We also installed the Amazon Prime video on demand and NetFlix apps and I’ve nearly convinced the wife to ditch cable altogether.
These devices are awesome and well worth the money.