Donnie Darko is a 2001 American science fiction psychological thriller film written and directed by Richard Kelly. It stars Jake Gyllenhaal, Jena Malone, Maggie Gyllenhaal, Drew Barrymore, Mary McDonnell, Katharine Ross, Patrick Swayze, Noah Wyle, Stu Stone, Daveigh Chase and James Duval. The film follows the adventures of the troubled titular character as he seeks to find the meaning behind his doomsday-related visions.

If you are someone that likes for your movies to be cut-and-dry, then this is not the movie for you. First of all, this film is designed to be one big think tank for its viewer; it encourages its audience to digest the material in a unique way and the variety of symbolism is simply unmatched. The oddities are paired with imagery that some may call equally "bizarre", and there is an unwavering consistency of this up until the very moment that 'Donnie Darko' comes to an end.
My best advice would be for new viewers would be: Come with an open mind and don't watch this movie with the intent of understanding it. You'll enjoy it for the incredible value it has better that way.

This film is a genius example of embracing complexity without causing its audience an overbearing amount of confusion. This is done through the use of dialogue that "levels" or serve as a brief opportunity to provide (some) clarity to the overall picture.
[SPOILERS START HERE]
Some clear examples:
"I hope he doesn't look in the mirror and follow the path of fear"
Frank appears everytime Donnie looks in the mirror? Check
"I don't want to be alone" (Spoken to a therapist)
Frank appears anytime Donnie is shown as being alone? Check
(Explanation that sphere coming out of ones' chest leads people to their destiny)
Implication that Donnie's reality is making him consider suicide or some act of violence? Check again.
[SPOILERS END HERE]
I could go on and on and on using this point alone, but I think I'm making myself clear when I say: 'Donnie Darko' is simply brilliant in comparison to other movies that try to replicate its intricacy.

It's impossible to review this movie without giving a clear round of applause for Gyllenhaal's performance. His facial expressions speak well over a thousand words, and the controlled nature of his movements increase the intensity of the scenes in which he doesn't utter a single syllable. In interviews Jake has acclaimed this film as "one of his most proud accomplishments", and the accolades he has received for this performance are more than deserved.

A cult classic you need to watch!
I would recommend!