Mine's the same as Meagz's--Miss Saigon. Between the fall of Saigon, and then I recovered bit, and err, the ending, not sure what song that was I was just crying soo much and soo loud. I can get emotional in theatre but I never cried as hard as I did for that show.
On an experience, meh, I know how some people will react but...when Idina walked on stage to sing the last part of the show of what was supposed to be her last performance. It was just due to everything, what happened the night before, her not performing, Shoshana's great job in her place, getting to see her take her last moment and then the curtain call speech, it was just an emotional place. This particularly stays with me because I was bawling as soon as she walked on the stage and during the ovation and the screaming I tried to scream and cheer a bit but instead of cheering lots of crying noises just came out so I just clapped and didn't open my mouth again...
"If there was a Mount Rushmore for Broadway scores, "West Side Story" would be front and center. It snaps, it crackles it pops! It surges with a roar, its energy and sheer life undiminished by the years" - NYPost reviewer Elisabeth Vincentelli