Topic seems to come up often, tons of threads here and in the Home Theater section. The best is subjective and the answer may be different if you have one or thousands and how many are DRM protected. These are for your own or backup use, right? We can't talk about piracy here.
Many use MakeMKV to rip the DVD to a mkv file, and then Handbrake to convert to an iTune/ApplTV friendly file. Then drag that file to the "automatically add to iTunes" folder. If your DVDs lack DRM, then you could skip the MakeMKV step.
There are several scrips around that automate the process, and many use subler to add/edit meta data like titles and descriptions. There are a few paid programs too I think.
There are probably several different ways to skin that cat, and best depends what is best for you.
If all you want to do is avoid carrying a bunch of physical disks around, use Disk Utility to make a CD/DVD type image of them on your hard drive. These images will then play just like a DVD via the DVD player.