I was about to say "take the hobbit!!!" But then I saw it would be your only game - personally I think that would be frustrating. TH is like a long-playing role playing game; it has some fast parts and lots (!!!) of multiballs but you also need to be ok with the long ball times and it isn't the best flow game of all time. If it's the only game you may not have enough variety in your collection. IMO You need two games - three is better - when you get pissed off at one you can switch to another
That said, TH is amazing. It's amazing. If you like MM, I think you would like TH. Similar theme, lots of pop up mechs, great callouts, huge dragon, INCREDIBLE light show. It does not have a toy like th castle, but IMO TH is incredibly underrated. I think the lack of a "main" toy is keeping people from understanding what a great game this is
Tough decision. I think TH is way more fun than JP or GOT but if it's your only game it may just be too limiting. I am not sure if there's any game that can stand by itself forever