This is the best piece of film crit I've ever read.
Donnie Darko follows a boy of superior intelligence whose emotional problems propel him on a very strange trajectory through a tangent universe. Donnie’s journey begins when he dreams about a rabbit telling him to leave the house. He follows the rabbit, and escapes being killed by a falling airplane part of unknown origin. But the rabbit tells him that the world is going to end in twenty-eight days. Donnie’s been given life and death at once.
Donnie Darko boldly attempts not only to transcend the time travel conundrum, but to link it explicitly to the biggest question of all: Does everyone die alone?