I seldom leave a movie theater with a big lump on my throat but when I saw The Sixth Sense, I just can't help but be moved by the scene where Cole (Haley Joel Osment) finally "communicated" with his mother (Toni Collette) in the car, telling her of how her grandmother watched her mother danced. It's not much about the scene or the dialogue but more of the way Toni Collette's expression slowly changes from trying not to breakdown ... until she did. And yes, I cried with her.
Other great movie scenes in random order :
1. The first 30 minutes of Saving Private Ryan
2. The Russian roullette scenes in The Deer Hunter
3. Bonnie and Clyde's death scene
4. The secret revealed in The Crying Game
5. Merryl Streep giving up her son to Dustin Hoffman in Kramer Vs Kramer
6. Mary's gel in There's Something About Mary
7. "You talkin' to me ?" in Taxi Driver
8. Discovering Norman Bates and the killer in the original Psycho
9. Linda Blair's head making a 360-degree turn in The Exorcist
10. The opening sequence in The Lion King
I'm sure there are more but these are the ones I can think of right now. They are forever planted in my brain.