The 11 Best Sci-Fi Movies You Can Stream Right Now, From 2001 to Ex Machina

But at its heart, Back to the Future is a sci-fi movie--and one of the most perfect examples of the genre. Marty McFly (Michael J. Fox) is your typical cool '80s teen who just so happens to pal around with a mad scientist, Doc Brown (Christopher Lloyd), who invents a time machine. Through a series of unfortunate events, Marty ends up getting sent back to 1955, where he befriends the teenaged versions of his parents and does his best to dissuade his mom from having the hots for him. By messing with history, Marty's messing with his own future and slowly being erased. But he manages to right the past, find his way back to 1985, and give those fun-loving kids a taste of what rock'n' roll should sound like.