1. If you want lossless copies of your movies, you can use DVDFab to rip them to ISO's or other lossless formats. The downside here is that the file size per DVD is huge. The plus-side is you can always re-burn a dvd fairly easily.
2. If you use handbrake or DVDFab you can convert them to a digital video format (.mp4, .mkv, etc) and store them, the file sizes are smaller (varying, depending on your preferences of quality), but the video will have some lost some potentially-discernable quality and it will be a little more difficult process to get onto a DVD.
I use method 2, using handbrake (and AnyDVD to strip encryption), and store them all on a server in my basement.
I then have devices attached to my TV's so we can just stream the movies from the server instead of using the discs.