I've remembered several other scenes/quotes since my initial encounter with this thread. One is Cleavon Little's classic quip upon returning as a Marshall after being sentenced to hang. His friend, deliriously happy to see his buddy alive, says, "They said you was hung." I won't post Cleavon's response but you can probably divine the jist of it even if you don't remember the exact wording.
1. Saving the handcar instead of Cleavon & friend
2. The executioner and his queue
3. Harvey Korman's incredibly spewed listing of every possible kind of ne'er-do-well
4. The Teutonic Titwillow.
4a. "Ahm tahrred"
5. "We gotta build a fake town before sunrise"
6. "Anyone moves, the nig* gets it!"
7. "This is my shooting hand."
8. "Don't shoot him, you'll only make him mad."
9. "We give 'em the old number 4(?). Ride into town, a-whoopin' & a-hollerin' and..."
10. "Someone go back and get a whole s*tload of dimes."
11. "It's twoo! It's twoo!"
12. The climactic fight scene, spilling out onto other soundstages and cultures.
13. Mel Brooks the director managing to make the few serious-appearing moments in the film stick out as oddities.
and, many, many more.
Great movie.