Best HTPC setup

Thanks for the info! You're system sounds a little $$... what are the benefits of going with a separate backend/frontend setup? I didn't know you could stream to an XBOX from MythTV.... could you suggest an upgrade path starting out with an all-in-one box and then moving to a separate backend/frontend solution? I wouldn't mind have a separate backend server, but I'll have to pull cable to my office, and I hate doing that, although I guess I could go with an hdhomerun solution.

I tried throwing on Ubuntu on an old P3 I had... it only has 128MB of ram, but I figured it should be good enough to play with. Unfortunately using the LiveCD was pretty much impossible, so I'm going to try just installing it and seeing if I could at least use it... otherwise, I'll see if I can't score a free 128mb stick of RAM from some people around here with old computers.

I have a friend who is a big Gentoo proponent but told me since I have a 2 year old and a baby on the way I probably wouldn't have time to really learn it so I should stick with Ubuntu.

The big downside to going with Linux for me, is probably zero possibility of getting a DirecTV PCI card, but who knows if that's going to happen anyway or how restrictive that's going to be. The bigger downside is uncertain support for legally downloading and playing high definition movies... but if that ever becomes a big deal for us, i can always switch to windows...