Freeware such as DVD Decrypter and DVD Shrink both work as good or better than the pay programs out there. As a matter of fact many of the pay programs are nothing more than a collection of freeware tools that they charge for.
If you pay for any software I'd recommend putting your money towards Nero 6 Ultra which is a very stable and comprehensive burning package that includes Recode 2 which is very similar to DVD Shrink (it was actually written for Nero by the same guy that did Shrink).
A handy tool to have is DVD43. It's a small free app that runs in your system tray and disables the copy protection found on factory DVDs. It helps to run it when you encounter the rare title that gives Shrink encryption errors and is necessary for Recode since Recode doen't include a ripper of it's own. Here's a link:
http://dvd43.com/
You'll also need the patin-coffin layer for DVD43 to work:
http://www.mtc-comp.com/vso/patin-couffin_setup.exe