Perhaps it's the romantic sucker in me, but this exchange is a winner:
Marian: I'm sure I wasn't the only one to go on with my life their must have been plenty ofwomen for you over the years. Indy: There were a few, but they all had the same problem. Marian: Oh yeah? What's that?? Indy: They weren't you, honey.
When I saw the film in the theatre, pretty much the entire adult audience "Aaaaw"ed during that scene.
Her great big ol' smile helps that, too.
At the end when Indy and Marion FINALLY get married. The wind blows the door open, sending the iconic fedora landing at Mutt's feet. He picks it up and almost puts it on before his dad snatches it away as if to say, 'Close, kiddo, but not yet."
To wit and to match what was written about illumination in The Last Crusades' Heartwarming entry, Mutt doesn't treat the hat as a prize. You can see him hold and look at it with reverence and respect as if the hat itself contained some sort of power. It's also perhaps the first time that it really hits Mutt that his dad is THE Indiana Jones; that his dad is this really amazing man instead of a deadbeat that he's thought all his life. He's experiencing for the first time in a very real way the sort of awe all children have at their invincible fathers.
Indy discovering he has a new family after his father and surrogate father Marcus Brody have passed away.
The warm smile of respect on Indy's face when he mused how he had found kindred spirits in The Interdimensional Beings:
"It wasn't gold, it was knowledge; knowledge was their treasure."
Indy and Marion finally getting married and Indy bringing their son and proudly linking arms with his new bride and son in front of the church. Cheesy yes, but sweet.