Well I decided I needed an HTPC to complete my home theatre setup. It'll be used as basically a DVD player, with the benefit of playing movies stored on my main computer. My wife uses DirecTV's HD DVR, so there's no need to have a full blown HTPC setup.
I wanted it be pack quite a punch, since it will crunch 24/7, too, so I'm using a Q6600 GO cpu, 2GB of 800 ram, IDE DVD burner & 250GB hdd, since all those parts I have laying around. The IDE stuff will work well, and the cpu I just pulled out of my main rig and replaced it with a Q9450. And did I mention it'll be overclocked and crunching, too?

PSU will be an Antec EarthWatts 500, since I have one. It's 80+ certified, and doesn't have long cables like some premium PSU's, great for this install.
Here's a thread on it's progress.
First off, here's an Aspire Qpack case I've had laying around, it's one of the better cooled hatbox cases around, with a decent amount of room-

Next is an Asus P5E-VM mATX motherboard with HDMI out, full range of overclocking features, and pretty beefy regulation-

For cpu cooling, I modded the case to try and fit a Thermaltake Big Typhoon, but it wouldn't clear the psu. So I used a Zalman 9700 LED, which will help airflow, since instead of blowing air down on the mobo, it pushes to the rear, and out the case's rear 120mm exhaust fan. Here's a pic of the install-