Well, if you want the very best quality on full backups, you’ll have to use something like DVDMaestro and CCE or Scenarist (extremely expensive). These take a lot of expertise to use, so I’d go to doom9.org and study their tutorials.
There are simplier solutions that give excellent quality depending on how you want to use them. DVD2One and DVDShrink are easy to use and DVDShrink is free! You may have to exclude menus, or cut out foreign soundtracks to get the movie close to the correct size to put on a dvd R disk, and you still might have to compress the movie a little. I’m using DVDShrink and Nero to backup dvd’s and have been very pleased with the results.
Go to doom9.org or dvdshrink.info and go through the tutorials.