Is Magnolia (1999) sci-fi? Probably not, it's more of an oddball film. It's long by Western standards, a good three hours or so, mostly taken up with the small-scale dilemmas of a collection of characters. A rare sighting of Tom Cruise in seriously good acting mode is found here. There's another in Interview with the Vampire but I haven't come across any more yet... even rarer, the film does not revolve entirely around him.
This is not the point. This is a difficult film to watch due to it's length and pace but it is my mission in life to get as many people as possible to see it through to the end. Find a way. Let yourself connect with one of the characters. Be sentimental. Or just sit back and enjoy the unearthly beauty of the Aimee Mann soundtrack. Just as the characters are beginning to make progress with their dilemmas, and in some cases to reach out to one another, the film delivers an ending sequence that literally left me slack-jawed and on the edge of my seat for the last twenty minutes. You won't guess it unless someone else has told you. It's the best ending I've seen to any film, delivering a powerful message about the futility of human endeavour in the face of the power of nature or chance.