In the Fall of 2006 I needed a small but powerful computer which I could put in a closet and run large software analysis jobs overnight (see cqsat). I got this combination with an Intel dual core CPU @ 3.2GHz custom built at Central Computers in downtown San Francisco. It's worth noting that central offers pretty low prices and is the only computer store near the busy Moscone convention centers. Customer service however is even cheaper than the prices and I did not have a good experience buying this computer (they scratched up the casing and the manager then played games to cover up). So this is a favorite store of mine to check out hardware in the flesh (so to speak) before buying guilt-free online.
The Antec Minuet 300

In terms of external connectors it's got what you would expect, but it is missing a 9-pin serial connector. This might be a consideration if you are going to home-brew infra-red components ala. lirc. The box has a front firewire connector, this will be a plus if you have an HD set-top box.
The ASUS P5L-VM 1394

Other
Hauppauge WinTV-HVR-1950 USB
HDHomeRun ethernet dual digital tuner