Endgame versus Back to the Future (Spoilers)
On at least two occasions, Endgame basically mocks Back to the Future as 'shit'.
Well, sorry, but even if Endgame's multiple timelines take on time-travel makes more scientific sense than Back to the Future, it robs time-travel of any real sense of dramatic conflict.
Unlike Back to the Future, and most other time-travel films, where there is only one timeline, Endgame offers multiple timelines meaning that Captain America and Iron Man could go back in time, kill their past selves and trigger a nuclear war that decimates millions, without creating a paradox and thus doing any harm to themselves or their friends/family members within their own timeline.
There is no onus on the characters to be careful. Whatever damage they do had no impact.
So, I'm sorry, as enjoyable as Endgame is, and as scientifically coherent as it may be in contrast to Back to the Future (which really doesn't stand much scrutiny when one thinks of it - if there's only one timeline that means everything is set, and by going back in time to change the future you basically set up a paradoxical series of events that ultimately preclude the need to go back in time), I'd still argue the following from a dramatic/entertainment perspective:
Back to the Future trilogy > Avengers: Endgame