Steve Rogers/Captain America
As Endgame draws to a close, Steve volunteers to bring the Infinity Stones to their own timeline. Hulk, Sam, and Bucky stick around to await his return and panic when he doesn't come back in the designated time. As Bucky and Sam search their surroundings, the former notices an older man sitting by the lake nearby and encourages Sam to approach him.
When Sam gets closer, he realises that the old man is actually Steve, who has aged a good 100 years or so. Older Steve tells him that he used his last time jump to go back and marry the "love of his life" Peggy Carter. He lived out a long and happy life with her and came back to pass on the Captain America mantle to his friend, Sam. He jokes that he finally went and "got a life," just like Tony was always telling him to.