I think the ending to Jaws has virtually every other film ending beat. Who can deny the profound depth of Roy Scheider and his incredible exploding shark?
"Smile, you son-of-a-bitch!"
Every film should end like that.
Other favorites:
Yojimbo
Seven Samurai
The Untouchables
The Godfather Part II
Army of Darkness
Rushmore
The Texas Chainsaw Massacre - The original, not the sloppy, over-stylized remake!
Reservoir Dogs
Nick Andopolis: Hey, I believe in god, man. I've seen him, I've felt his power! He plays drums for Led Zeppelin and his name is John Bonham, baby! "
- Freaks and Geeks
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Disaffected Youth #1: Hey, there's that cannonball guy. He's cool.
Disaffected Youth #2: Dude, are you being sacrcastic?
Disaffected Youth #1: Man, I don't even know anymore.
- The Simpsons