So if you haven't checked it out yet, I heartily recommend giving HandBrake a looksee, because it has become significantly more powerful since the last time I used it en masse. HandBrake 0.9.3 introduces universal video input: it can now convert practically any format of video into MPEG-4, including DivX AVI files (very nice for putting those bootlegged Doctor Who episodes on an iPod or iPhone or any other portable video device). The video quality has been greatly improved, with many more presets and options available. Syncing of video and audio is said to be fixed, but I never saw any problems with that to begin with. I have however found that HandBrake 0.9.3 is far more stable in Windows Vista: previously, I had to re-install the program every time I wanted to convert a new DVD. Version 0.9.3 has fixed that bug: I've "fired it at the walls" (my own terminology for probing software for its limits) quite a bit over the past several days, and it keeps coming back and asking for more.
If you are using a Windows machine, you will likely have to purchase and install SlySoft AnyDVD, which does the actual work of decryption of a DVD. But HandBrake itself is free and open-source, and is available for MacOS X, Linux and Windows.