"Ya hear that, fellas? We're competing with Archie and Jughead." (Gordo referring to Glenn and Carpenter, though who he means as which is debatable.)
Gordo's wife asks if he's ever let her down. Gilligan Cut to her trying out the sink in their new house and getting a dribble of filthy water.
Everything with Harry Shearer and Jeff Goldblum.
"Our Germans are better than theirs."
The entire meeting in the Pentagon after the launch of Sputnik can be considered this. LBJ is an unapologetic Large Ham and constantly misunderstands the accent of the Von Braun expy ("Pod" as "Pot", "Specimen" as "Spaceman", and "Chimp" as "Jimp"). Capped off when Those Two Guys show a reel of various daredevils and circus performers as Astronaut candidates, and President Eisenhower demands Test Pilots which causes everyone to react in horror.
One of the rocket launches has the top pop out, along side a champagne bottle sound.
Just about everything with Lyndon B. Johnson.
The scene in which two officers discuss the unsuitability of Chuck Yeager for the program, unaware of the fact that he's just down the bar from them and can hear every word. Double bonus points because:
This actually happened; AND...
The bartender in that scene is played by the real Chuck Yeager.
Al Shepard's launch gets delayed, leaving him stuck in the capsule. After a while he tells Mission Control that he really needs to pee, something nobody had made any provisions for. Gilligan Cut to shots of people running tap water, pouring tea, coffee, etc. Finally, clearly irritated, he says, "Permission to urinate."