The answer to this question is not a simple one. LOL! For me, there are different elements of "best." For sheer fun and immersion, I think GOTG, Cosmic Rewind is the best. The intro, backstory, FX, ride system, everything all works so well together, and then there's the MUSIC! So yeah, I think that's the "best." That said, I think Matterhorn Bobsleds at DL is an amazing ride. Loads of fun and over the years it has been enhanced with some nice FX. It is a must do ride for me and my kids every visit. Of the dark rides, I'd have to say Peter Pan's Flight is the best. Even if you don't have an emotional connection to the film, it's just a lovely ride. Indiana Jones is another truly amazing ride I love a lot that never fails to entertain. Even the queue, with its interactive elements is cool. And then there's GOTG, Mission Breakout. When they announced the retheming of this ride I was furious. Why mess with a cherished ride? Disney could afford to build an original attraction. And the timing of this seemed rushed to get something in place to synergize with the release of GOTG, V2, so the whole thing just seemed contrived to me and doomed to fail. Well, all of that stuff was true, but, shockingly, the reborn ride is actually better. I can't stand the exterior theming, but the queue and the ride itself is a home run.