I ripped to MKV first so I could keep a backup of basically what is the "full DVD", that way if the disc ever got scratched or lost I could simply make a new one. By having a master in a clean format I can rip it to any other format I like in future with minimal loss of quality. My master files take up 440GB on my NAS whereas the MP4 versions take up 221GB - basically half the space. I am not too worried about the space given that my movie collection doesn't increase very fast, I think I have about 6 or so DVD's that I bought in the last six months that I still need to rip. I merged the MKV files from LOTR EE using the mkvtoolnix utilities (mkvmerge specifically), then ripped to MP4. Link: http://www.bunkus.org/videotools/mkvtoolnix/. The biggest pain was sorting out the different subtitle methods as I mentioned earlier, it took a few attempts to get right per movie.
I picked up a WD TV Live about a month ago. It wasn't that happy reading files off of my Airport Extreme based 'NAS' and kept forgetting the connection. Since I've moved a 4TB onto the USB port at the back it's much happier. It's so much easier than the old HTPC it replaced, or moving a laptop around and plugging in HDMI. I've found the media library aspect where it downloads thumbs etc is a bit unreliable though. Does it play everything I throw at it? Yes. Any quirks? Only the built in library issues and you can off the whole library if needed. Quality? Great and if you have any files with audio sync issues it's easy to adjust as needed.
I'd like either a remote controllable software Windows media player or a hardware media player box with big font and icons so I can read it on a small (10") screen sat from my sofa. Nearest i've found is a particular skin on Mediaportal. Finding it very hard to find something readable.
I went for the WD Live TV, not pretty but quite functional, havent found any formats it wont play yet.
I know, you spend that kind of money and you want something bulky so you have spent your momeny well lol. sorry when i said not pretty i was refering to the UI rather than the actual physical item. thats fine (but small)