I've finally developed - somewhat organically over the last few months - my first HTPC.
It all started by buying a new Panasonic P42V20 plasma with HDMi and networking capability. So, after several years of a component-only capable CRT TV I could at last attach my PC via HDMI and also plug the TV into the network.
Hooray! A DLNA-capable PC. Using serviio DLNA server I was able to overcome the limitations of Panasoni'c built-in firmware and watch pretty much any videos and access my music library/pictures. Using the HDMI connection I could use the TV as a second monitor, so had access to proper internet TV, especially when used with a Logitech K40 wireless keyboard/trackpad unit, which was able to drive the PC (in the bedroom) from the lounge.
Now I've just added a Hauppauge HVR-2210 dual digital tuner card. After a few days of fiddling it's now running MythTV under linux (and secondarily MediaPortal on Win 7). I am now recording and watching LiveTVl in glorious digital HD and 100% DRM-free. Sweet.
Last step will be to upgrade the PC monitor from a 4:3 LCD to a proper 1080p IPS LED LCD so I don't have to keep adjusting the aspect ratios! Blu-ray will remain a standalone player, since I need the analog DTS-MA/Dolby HDoutputs for my older HT amp (not to mention it's still not easy on *nix).
NVIDIA GeForce 260GTX
Win 7 w/Mediaportal
Arch Linux w/MythTV