DVD Decrypter, Smart Ripper, vStrip are all good rippers....bypassing the protection and putting the DVD/DVD iso/ or selected IFO/VOB files you require onto your HD.
DVDShrink includes a ripper but is not a stand alone ripper (but is excellent if a little slow) in the sense of what people call a ripper.........confused?............. you will be. The great thing about DVDShrink is its user interface, it hides all the hard work......you dont need to understand the mechanics of how a DVD-Video disk works (ifo/bups/vobs) all you *basically* need to know is 'will it fit on a DVD-+R?' and 'what can I dump if it doesnt'.
For general back-up usage DVDShrink is about all you need for DVD to DVD.... its when you convert mpeg2 video to mpeg4 (divx/xvid) and AC3 5:1 to mp3 2:1 audio thats things get a bit complicated.