Cassini HTPC v2 here: http://pcpartpicker.com/b/yUF
The main idea behind Cassini HTPC is a quiet, yet powerful PC used to play video with XBMC and take advantage of Steam's Big Picture mode. Cassini v2 served me quite well, but I bought a 1080p TV to replace the 720p and I moved to a Synology NAS (3TB RAID5) to store all my media and backups. With the Synology doing a fantastic job, the size of the GD06 case wasn't needed. With the increased resolution on the TV, the 5750 couldn't cut it.
I like the SG06, and wanted to make a little powerhouse this time around. I'm not an overclocker so I believe the H77 chipset and non-K CPU are a good match. Yes, an i7 is overkill. No, I don't care. The 3770S is a 65W TDP version of the 77W 3770, so I favored that for this small build.
PC is running Windows 8 Pro. Input is handled either by a Logitech Harmony 510 remote, Lenovo N5902, Lenovo MX Air mouse, or wireless Xbox 360 controller; depending on what the user is doing.
Case: $145.00 + $12.65 tax + FS |||| CPU, motherboard: $404.98 + FS |||| GPU: $235.98 + $20 MIR + FS |||| SSD: $214.99 + FS |||| RAM, cooler, PWM fan: $101.84 + $3.87 S/H |||| ODD: $44.99 + $18.99 S/H |||| Total = $1163.29