Don’t expect a straightforward timeline, because continuity is a mess with the Alien and Predator timelines (even if, as in this list, you choose to ignore tie-in comics, novels, and games). Predator: ...

Do aliens exist? Based on how many alien invasion movies there are, you'd be forgiven that there's gotta be some proof of extraterrestrial life—and that the aliens are out to get us here on Earth. But ...