For me it is Love Actually (2003). I recently watched it again. The script had already been forgotten over time, but when I reviewed it, I remembered almost everything. The film is very enjoyable. It tells us that love does not depend on status, on age, maybe to the same sex, maybe not reciprocal, maybe "for work", maybe in different languages. But it is all-consuming, creative, and without it there is no meaning in life. I would like to mention the role of Hugh Grant, I remember her the most in this film. And also pity Harry's husband, who was deceived. But ... life is life, and everything is shown in the film, so diverse, really occurs in reality, often evoking emotions "cannot be".
There's so many movies that I know by heart and can quote on any occasion. Most of them are humorous, but there's a few serious ones. Anyway my favorites include Tommy Boy, The Shawshank Redemption, Scooby doo 1 & 2 live action, Shrek, and the Big Lebowski to name a few.