I'm not really a crier, but there are a few things that I just can't handle. Taps, for one. I don't have to know the person, the circumstances of their death... anything. Just hearing Taps makes me well up. I think it's probably because it was when they played Taps that I realized my Grandfather was really gone.
The 21-gun salute has a similar effect. Stories of selflessness can get to me. Watching my children sleep does it sometimes.
And the movie Field of Dreams.
What about you?