I built a Home Theater PC. Silverstone makes some great looking HTPC cases, I got a black one that matches everything else. Optical drive is CD/DVD/DVD-RW/HD-DVD/BluRay combo, fanless power supply from ThermalTake, 1TB SATA hard disk, 4GB RAM, 1GB nVidia HDMI video card, and wireless LAN (onboard) and I was off to the races. It also doubles as a jukebox (using iTunes). I don't pass TV video through it, so I use the cable company's DVR for that, but I can stream NetFlix, or watch YouTube, or DVDs or BR or HD-DVD (short-lived, I know, but there are still some floating about, and the drive didn't cost any more than a BR-only at the time).
Keyboard and mouse duties are handled by a RocketFish RF keyboard and optical mouse. CyberDVD is the DVD/BR playback software (came with the drive - works GREAT).