hi, i use one that is really nice.
it can help you to convert your DVD to MP4, H.264, AVI, WMV, FLV, MKV, MPEG-1, MPEG-2, 3GP, 3GPP, VOB, DivX, MOV, RM, RMVB, DPG, etc, even rip DVD to HD video, like HD H.264, HD AVI, HD MPG, HD TS, HD WMV, HD MPEG 4, HD MOV, HD ASF, also convert DVD to audio, like MP3, WMA, M4A, AAC, WAV, etc. with super fast DVD ripping speed and excellent image and sound quality.
it can also do many video editing works, such as trim, crop, merge and so on.
Free download it here:
http://www.aiseesoft.com/dvd-ripper.html
Just have a try and i hope it will be helpful to you.