Yeager's aileron roll after breaking the sound barrier;
Yeager breaking the sound barrier in the first place. Everyone else who's tried has failed or died. He's never flown the plane. And he has broken ribs from a riding accident the day before. And then he nails it.
Recruiting Shepard for the astronaut corps ("Sounds dangerous." "It's extremely dangerous." Count me in.")
The astronauts sticking it to the program manager when he threatens Glenn's mission;
Glenn's ticker-tape parade;
John Glenn sticking up for his wife (who had a tremendous stutter at the time)
Friendship 7's launch. Complete with an epic use of "Mars" and "Jupiter" from "The Planets."
Yeager walking away from the NF-104 crash ("Is that a man?" "You damn right it is!")
"Go Hotdog GO!"
"And for a brief moment, Gordo Cooper became the greatest pilot anyone had ever seen." (Roll credits)