As long as there have been movies, there have been aliens—whether they are little green men or the nightmarish creations of H.R. Giger. And as long as there have been aliens on screen, there have been badass alien hunters for us to cheer on. You see, aliens make for the perfect bad guy. They always seem too tough, too smart, and too scary to ever be beaten, but they never count on having to deal with a Ripley or a MacReady or Arnold Schwarzenegger. Here are the 10 roughest, gruffest, and most all-around badass alien killers to ever hit the big screen.