Dvdrip is a GUI to numerous command line tools
including transcode which does the bulk of the work.
The dvdrip command provides an intuitive interface and
reminder of all the vast array of options available. Generally, load
your DVD, go to the RIP Title table and obtain the table of contents.
The largest one is usually the movie! If you are space restricted
(less than 10GB say) you may like to do one or more chapters at a
time. You can then begin the rip to produce a .vob file.