I recommend one for you that I have been using for more half a year.
its name is Aimersoft DVD Ripper.
It supports many formats conversion, such as DVD to AVI, DVD to MP4, WMV(Windows Media Player), MOV(QuickTime), ASF, 3GP, MPG, MPEG, FLV(Youtube), VOB, H.264, DIVX and so on.
A very powerful and easy to use tool, you can achieve it only through four steps.
1.Load dvd or load files to open dvd;
2.click “trim” or “crop” to edit video;
3.click “settings” to set the output options;
4.click “start” to convert dvd.
Can google Aimersoft