I use progie called WinX DVD Ripper which so far has worked very well. Typically I rip two formats. One an exact copy, which is a very large file in the range of 4 to 6 Gb. This I keep on a external hard drive for my PC or other future use.
The other I convert to a that Works well on the iPad and it gets stored on a Segate satellite portable drive.
It also works well to convert DVD recordings that I've made of movies or tv shows but that quality is not a high a resolution as when ripping 'produced' DVDs.
When it comes time to travel I load my of my wife's IPad with what ever movies we'd like to take.
dvd-toipad.com
It offers a number of conversion types.
Base cost was $35. Updates offered after Jan 1 cost another $35 for that calendar year.
Free upgrades for the calendar year. From what I can tell the upgrades which come about every three weeks a countering new anti piracy technology.
Simple to use....