You could use Mac the Ripper. That will give you a VIDEO_TS folder, which has all your DVD stuff in it. Another option would be to use Handbrake, or its newer cousin MediaFork, to encode the movies into .mp4 or .avi. This way, however does not preserve menus.
First of all, I am morally offended that you would think to back up content you own. Surely you realize that you are screwing the studio out of the chance to sell you another overpriced copy of the content you already paid for.
That said, for the whole backup, I use MacTheRipper 2.6.6? (where is 3??) and then burn the TS file with Toast 7. If you run into one you can't burn, check the forums for MTR settings to play with. I've been very pleased. Then I take the DVD (inkjet printable of course) and print a label directly on the DVD with an Epson R220. The personal artwork adds that little extra something...
If you want other than a DVD backup, or want to change the format, Handbrake is good. No experience with MediaFork here, but I'll have to go play with it.
First of all, I am morally offended that you would think to back up content you own. Surely you realize that you are screwing the studio out of the chance to sell you another overpriced copy of the content you already paid for.
Fast DVD Copy 4 is probably the best all in 1 DVD back up solution. It's also 1 of the most expensive at USD$99.95. Like they say though you get what you pay for. I wouldn't use anything else it's an amazing app.