One program I like to use is called
Handbrake. However I use this program 'after' I have extracted the DVD TS_Video folder to the hard disk drive. Handbrake uses an advanced format ability of the MPeg 4 X.264 (H.264) format. I normally save them as mp4 files but you also have the option of saving them into video containor formats such as mkv & avi. There is a bit of a learning curve to using Handbrake. And using the extended X264 abilities will reduce compatibility generally, however produce a very high quality video file. Outside of some of the professional H264 formats, X264 is the best lossy video format around.
Keep in mind high definition Blue Ray disks nowadays generally use H264 format.