Best and easiest program to use for DVD's and MKV files (or any file for that matter), is DVD Catalyst...hands down. The developer of that program...Mitch, is a good friend of mine. We talk daily about how to push the limits of the movie quality on the Nexus. I have hundreds of movies converted for the OG Droid, HTC Thunderbolt, iPhone 4 and now converting my whole library for the Galaxy Nexus. All my movies are 720p HD MKV's that are converted. You can do 1080p...but that would be overkill.