cheerjerker
A cheerjerker is a movie, TV show, book, play or story that induces emotional tears in the viewer when something really good and positive happens. This can include news items and news stories of a touching nature concerning a human interest story. Also, real life videos of heartwarming events as can be found in abundance on YouTube can be qualified as cheerjerkers if they move the viewer to be choked up with tears.
"Oh my God, 'It's A Wonderful life' is the biggest cheerjerker in history. There are a lot of great, emotional moments in that movie but the last fifteen minutes is an absolute nonstop water works."