My vote is for the Sixth Sense, too.
When Bruce Willis's character...oops... You mean people haven't seen it yet?
I bought it on DVD as soon as it came out. It chokes me up every time!
I've been told that Sophie's Choice would choke me up, but I'm kind of tender hearted to begin with, so I avoid tear jerkers in general.
Oh, don't forget:
Where the Red Fern Grows
I hate it when the dog dies!