If you want to rip BluRay or DVD to .mkv you can use MakeMKV. It's in beta(and free while in beta) for who knows how long. Also DVDFab Passkey is still in beta. Insert the disc, then drag & drop the entire set of video folders to a folder on your HD.
Sometimes one will work where the other doesn't. MakeMKV is more confused about "episodic" DVD/BluRay discs than DVDFab Passkey. Sometimes MakeMKV rips a "main movie" type disc much better/faster than Passkey. It's good to have both. Just be sure to disable Passkey while you are using MakeMKV.