For DVD ripping, I've found Handbrake does the job nicely. The couple times I've tried Bluray ripping, I've failed to get something usable. (One time I ended up with the director's commentary track...)

For playback, any Android tablet will do the job. The downside of the Kindle tablets is that you have to do a bunch of annoying stuff to install the Google Play Store, Google Play Services, and all that. Also, they're less responsive in terms of rolling out the latest Android features, bug fixes, security fixes, etc.

I got my daughter a Dell Venue 8 7840. It's got a microSD slot, so you can expand it out for lots of videos. It's got three cameras, for some weird stereoscopic stuff. It's got Intel Inside so... it's reasonably fast. It's got the most amazingly bright screen you've ever seen. It's currently running Android 5.1. Unclear if/when they'll bring over Android 6, but it's still Dell's current top-end tablet, so there's at least some hope of it staying current.