Chinatown and Gran Torino. Two movies that got me invested into the main characters and made me think nothing wrong could happen on their watch and then absolutely destroyed me with the way they ended.
The part of me that's romantic wants nothing more than the MC to settle down with Charlotte and adopt Emma (who shouldn't even be an LI if you ask me) is at war with the somewhat artistic part of me that knows that if things went tits up in the end, I would be absolutely gutted, but would fall in love with this game as well. And I am in for whichever one it is.
Seriously if you haven't watched the movies I mentioned above, give them a try. You won't regret it. And that will make the ending all that much better. When the cop says to the MC at the end, "Forget it MC, it's Hillside.".