Discounting the toddler years and the very early years, I'd say about two or three times. Once was when my mother had her second stroke and my father had an accident on the same night. Once was when I was really depressed due to a number of things, especially being humiliated daily at work.
I sometimes get misty eyed when I passionate about something or watching a really touching movie. But I don't cry often. If I'm down, I usually try and find something to do, usually gaming.