Donnie Darko
Probably the most unconventional coming of age film you will see, it constantly leaves you guessing.
I feel you can rewatch this over and over again and have a different view of the ending. Full of symbolism and emotional complexity this one really hits hard. One thing I love about Donnie Darko is that it doesn't insist upon itself, many films full of symbolism like this try too hard and it gets to a point where it becomes more about making you notice what it is trying to say rather than just conveying it naturally. Luckily, Donnie Darko doesn't fall into this trap and the meaning is expressed candidly.
A rare kind of storytelling that lingers in your mind long after the credits roll. A true masterpiece that everyone should experience at least once in their life.