The moment when Iron Man snaps his fingers to defeat Thanos is unforgettable. It was a self - sacrificing act that saved the universe. Also, the scene where all the snapped heroes return through the portals was amazing. It gave hope and showed the power of teamwork among the Avengers.
One of the most memorable moments is when Captain America wields Mjolnir. It was a really cool moment that showed his worthiness. Another is the final battle where all the heroes come together. It was epic seeing them fight side by side against Thanos.
Definitely when Hulk uses the Infinity Stones to bring back everyone who was snapped. His struggle with the power of the Stones was intense. And the emotional goodbye to Black Widow was also very memorable. She sacrificed herself for the Soul Stone, and that was a very poignant moment in the story.