In the Jimmy Kimmel bit, I especially loved the standing ovation for MJ and Lloyd. For a movie made 30 years ago, it must be gratifying to know that one's work is still so beloved by audiences everywhere.
Getting back to the poll:
BTTF I stands in a league of its own. As good as the sequels are, I don't think that either of them is worth comparing with the first. It's on a level with E.T., The Wizard of Oz, Toy Story, etc.
BTTF II is incredibly inventive like the first film, taking us through tons of time travel tropes in a wonderfully breathless pace. In a somewhat pre-digital age, the blending of the scenes where the same actor is playing more than one role -- that remains a special-effects masterpiece to this day. The only problem with it is that it doesn't really function as a standalone movie. It barely has a standalone beginning; the last third of the movie assumes that you're very familiar with the first one (which, to be fair, most people are); and it has a huge cliffhanger rather than a satisfying ending. As such, it lacks a little bit in the "human warmth" department. Mind you, this is my one problem with this film, which I otherwise love.
BTTF III brings back in fans who were lost and confused and who found themselves no longer caring about BTTF II. It has the emotional heart that was missing in II. Despite picking up from a cliffhanger, it's a fairly straightforward story with a satisfying beginning, middle and end.
Also, it surprises me that this isn't pointed out more often, but the character arcs of Marty and Doc reach their ultimate conclusion here. Throughout the other two movies, Doc represents reason while Marty represents emotion. In the third film, their positions reverse. The great moment where Marty sees his own tombstone and says, "Great Scott!" and Doc says, "I know. It's heavy!" is not only a very funny line, but it's also indicative of just how much effect these characters have had on each other. By the end of the trilogy, both characters have learned everything they can from each other, and have balanced the other one out. I think that reason, as much as anything, is why there haven't been more movies. The characters' arc is already complete.
If there's a downfall to III, it's that the jokes are finally starting to become too obvious and repetitive -- i.e., the whole "Mom, is that you? I had a terrible dream" bit. Also, the amount of relatives that these characters have which are spitting images of each other begins to reach ridiculous heights. Think of it this way: In the first movie, Marty meets Lorraine's parents, who are played by believable and funny actors specifically hired for those roles. If the first movie had been shot in the same way as the other two, then Lorraine's mom would have been played by Lea Thompson in a funny wig, and Lorraine's dad would have been played by Michael J. Fox in a bald cap, taking us out of the moment.
(Having said all that, I think that if there hadn't been contract issues with Crispin Glover for the sequels, he would have made a great Seamus McFly.)
Again, these are small problems in my estimation. All of these movies are in my top 20 films of all time. But I think that's the difference between the films. II is incredibly clever but a little lacking in heart. III has lots of heart but isn't nearly as clever. In my estimation, I remains the best because it's the perfect balance between the two approaches.
I laughed at a few of the jabs at our real 2015, but Kimmel could have mentioned the end of the Cold War (and general threat of a massive nuclear holocaust), the surge of the global gay rights movement and the implementation of universal heath care as things we have gotten right... Everything Sucksism humor is lame, topical gags about the Cubs actually doing well this season aside.
