Batman, because it slapped a lot of false perceptions in the face.
I also loved Cap's and Logan's. They're tied for a close second.
I can see why any of the 4 would be picked
They are all special in there own ways
4. Iron Man - This was absolutely perfect in concept but fell totally flat on its face for me in execution. He takes so. damn. long. to say that line before he snaps his fingers, I honestly kept expecting Thanos to just smash his face in and take the glove back. It's legitimately my biggest problem with Endgame as a movie.
I think Tony struggling to get out the words was more due to the gems killing him than trying to create additional drama.
And Thanos also sat patiently when the Avengers Assembled. Say what you want about the big guy, he believes in fighting fairly and gracefully accepting defeat.
No way he'd sit and watch Iron Man struggle through exhaustion to snap his fingers (no moreso than the other version just gave up and said 'you win' when Thor buried Stormbreaker in his chest), because at that moment in time he isn't actually defeated yet.
Boy, I sure hope nobody introduces you to Anime.He takes so. damn. long. to say that line before he snaps his fingers,
Watch the scene:
Thanos only realises that Tony has the stones at 0:47. By 0:52 Tony has absorbed the stones and is ready to snap. From that point on, Tony could have snapped anytime he wanted to. He didn't need to say "And I am Iron Man", but it was absolutely in-character for him to do so. So in other words, Thanos had 5 seconds tops to cover a not inconsiderable distance and rip the stones away from Tony before he could snap.
After that, Tony would have just snapped early if he saw Thanos rushing towards him. Besides, there's always the possibility that one or more of the other heroes could have distracted Thanos to buy Tony a little more time - Cap and Thor were both back on their feet when Thanos' army was dusted.
There is also the additional factor of Thanos' shock - he genuinely thought that he had won and his facial expressions clearly imply that he was struggling to come to terms with his defeat (he only accepts it after seeing his whole army disintegrate). In a way, its a neat callback to the earlier scene between him and Nebula where he says that the arrogant never suspect anything.
In this case, Thanos' arrogance led him to underestimate Tony and not realise that the stones had been taken until it was too late.
Boy, I sure hope nobody introduces you to Anime.
I think the criticism that Tony takes too long to say the line is meh. That to me is a nitpick. If you want an excuse for why the scene plays out that way Thanos is both in shock and knows he is defeated. So he just accepts his fate. Trying to add something Thanos lunging at Tony or just having Tony do it in a rush is what they call in wrestling overbooking the finish. Why do all that when how it happens in the movie allows it to sink in more for the audience?