We asked the BuzzFeed Community to tell us which sad Marvel moments showcase how incredible the MCU actors are. Here are some of the best responses:
There are some massive MCU spoilers ahead!
1. First, in Thor, when Loki found out that he wasn't a true Asgardian and confronted Odin, and even though it was his first MCU movie, Tom Hiddleston proved to be one of the best actors.

2. In Avengers: Endgame, when Pepper put on a brave face when Tony was dying, and Gwyneth Paltrow just delivered during this scene.

3. In Black Panther, when Killmonger told T'Challa where to bury him after their fight, thus allowing Michael B. Jordan to prove he played one of the best and most complex MCU villains.

4. In Spider-Man: Homecoming, when Peter was trapped under the rubble, which led to an awardworthy performance from Tom Holland.

5. In The Falcon and the Winter Soldier, when Bucky realized he was free of Hydra's control, and Sebastian Stan gave one of his best performances.

6. In Avengers: Infinity War, when Wanda heartbreakingly had to kill Vision in order to destroy the Mind Stone, and Elizabeth Olsen and Paul Bettany showed us how brilliant they are together.

7. In Avengers: Endgame, when Scott returned from the Quantum Realm five years later, which led to one of Paul Rudd's most heartbreaking moments ever.

8. In Black Widow, when Yelena visited Natasha's grave, and Florence Pugh performed this moment so perfectly, as only she could.

9. In Agents of S.H.I.E.L.D., when Fitz was operating on Daisy as Leopold, and Ian de Caestecker proved to be the emotional heart at the center of the series.

10. In Avengers: Endgame, when Natasha sacrificed herself on Vormir so Clint wouldn't have to, and Scarlett Johansson was simply amazing in this scene.

11. In Iron Man 3, when Tony had several panic attacks, and Robert Downey Jr. was able to convey them in an honest way.

12. In Captain America: Civil War, when Steve attended Peggy's funeral, and Chris Evans broke down in tears.

13. In Captain America: The Winter Soldier, when Steve told Bucky to "finish it" while they were fighting, and Chris Evans demonstrated why he will always be the greatest Captain America.

14. In Guardians of the Galaxy Vol. 2, when Yondu died after saving Peter from his father, and Michael Rooker made literally everyone in the movie theater weep.

15. In Avengers: Age of Ultron, when Wanda broke down after Pietro died, and Elizabeth Olsen said so much without saying a single word.

16. In Black Panther, when T'Challa reunited with his father in the ancestral plane, and Chadwick Boseman showcased his dynamic range as an actor.

17. In Avengers: Infinity War, when Gamora realized that Thanos was about to sacrifice her on Vormir, and Zoe Saldana gifted us with this wordless heartbreak.

18. In Avengers: Infinity War, when Peter was dusted and begged Tony to let him stay, and this was just one of many times Tom Holland's crying face made us sob.

19. In Agents of S.H.I.E.L.D., when the team said goodbye to Bobbi and Hunter with a "spy's goodbye," and Adrianne Palicki and Nick Blood broke us just by nodding their heads.

20. In WandaVision, when Wanda described to Vision how her grief is like drowning over and over again, and not to sound like a broken record, but Elizabeth Olsen crushed it.

21. In The Falcon and the Winter Soldier, when Sam wiped the blood off the shield, and Anthony Mackie's pain spoke volumes.

22. In The Avengers, when Bruce reveals that he tried to kill himself shortly after he became the Hulk for the first time, which might be one of Mark Ruffalo's best performances in the MCU.

23. In Agents of S.H.I.E.L.D., when Daisy said goodbye to Coulson before he died at the end of Season 5, and it's just another reason that Chloe Bennet and Clark Gregg deserve more praise for their work on this show.

24. In Avengers: Endgame, when Thor got to see his mom alive again, and Chris Hemsworth showed how powerful it can be to just hold tears in your eyes.

25. In Guardians of the Galaxy Vol. 2, when Drax told Mantis about his family and Mantis sensed his sadness — this scene proved how amazing Pom Klementieff is.

26. In Avengers: Infinity War, when Okoye watched as T'Challa was dusted right in front of her, and Danai Gurira was able to convey so much pain and loss.

27. And finally, in Spider-Man: Far From Home, when Happy saw Peter working on his new Spider-Man suit after they both opened up about losing Tony, and Jon Favreau just knew how to make everyone emotional with a single look.

We can't fit everyone into one post, so what other MCU actors had such great performances, they made sad scenes more emotional? Tell us in the comments below!
Note: Some submissions have been edited for length and/or clarity.