My Girl will do that to you. I walked into the theater a 6-year-old boy and walked out an 80-year-old, world-weary war vet, like Matt Damon at the end of Saving Private Ryan.
My sister watched it with her daughter (who I think is like 8). At the end of the film, my sister was in floods of tears, and her daughter was pissing herself laughing.
Running around the house going "His glasses, he can't see without his glasses!", doing the accent and everything.