The idiocy of far too many video codecs surviving continues to amaze me. VLC Media Player seems to be the most flexible for PC playback. The $100 "WD-TV" media server gizmo seems the most flexible for TV playback. I just put all my media files (videos, images, music) on a couple of terabyte drives, attach the drives to the WD-TV (USB connections) and onto TV via an HDMI cable. No PC involved apart from the download stage. So I have the LLVJ, 300+ downloaded movies, home videos (from the 1950s digitised to current 1080HD), jpegs of all my archived photos (Jpegs only), all my digital music, instantly available on my 70" HD TV, connected to the home theater sound system.
WD-TV. That certainly seems to be the magical $100 gizmo at the moment. There are still codecs that it cannot play, but much fewer than any other device or software I have tried to date.