Black Panther vs Killmonger at the end of the movie.

Spider-Man V.S Mysterio! The visual choices for his spidey-senses were really stunning! Plus, I enjoy hallway fights so that's also another reason for me to choose!

My favorite was Black Widow vs Hawkeye in Endgame not only was that super emotional but the fight choreography wasn’t half-bad. Thor vs hulk was amazing in Ragnarok; though emotionally I would say Thanos vs either Captain America and Iron Man were really meaningful and fun to watch. To choose another one I also feel like I should mention Captain America and Winter Soldier in The Winter Soldier that was absolutely astounding. Abomination vs Hulk was also fun to watch.

I will say tho from what I’m hearing about Shang-Chi I think these are soon going to be easily outdone and I can’t wait to see it in theaters.

I liked Iron Man vs. Iron Monger in the first Iron Man. It was the first final battle of the MCU and sort of established Tony as a superhero in-universe.

Thor vs. Hulk on Sakaar! It had suspense, humor, and great action! It's one of my favorite scenes in the movie. We finally get a glimpse a Hulk's personality. Most importantly though, it sets Thor up to be even more powerful and self actualized.

Spider-Man vs. Vulture

Daredevil vs. Kingpin

Daredevil vs. Bullseye - Duel at Clinton Church

A lot but spidy vs mysterio

Captain America The Winter Soldier is #1. Nothing comes close to that in the MCU imo.