yea ive had a couple problems with running out of RAM, but 3GB solved that problem...
All of these are great solutions, but if you really want the easiest I'd have to recommend Pocked DVD Wizard (google it) It costs like 30 bucks but that comes with just about a lifetime license for all new versions for life, just select what part of the disc is the movie (it tells you by how long each one, obviously the longest running cell is the movie) and it will not only give you a preview of the movie while you set it up, but it also supports SO many devices (ALL the ipods/iphone/PSP/ just about anything that supports video) and not only does it decrypt, but converts, and will even save it right to the device it drag and drop is supported.
Set its priority on high and enable automatic PC shutdown, go to bed, and you've got a movie waiting for you in the morning!
Lol sorry I sound like an advertisement, but it really has been the best program I've ever used for this kind of work, I rip a movie just about every night and it always works and always comes out perfect for the device, it really works well for the ipod touch
Anyway, you can do all the other solutions if you have time and don't want to pay, but if you want an all-in-one then go for it...its worth it...
BTW I think its only Windows, so your SOL if you dont have an intel iMac or a PC