Aliens will soon be descending on the western front in Cowboys & Aliens. In the movies, aliens have always come down to Earth to either greet us or eat us. Sometimes the aliens are a masterpiece of genetics and intelligence. Other times they are just dopey shmucks who just sort of wandered onto our planet accidentally. Hopefully when it happens for real, they’ll be the latter. We pulled up a list of the best and worst aliens, rated by their bad@ssery. Check out the gallery after the jump.

In early July, 1947, a mysterious object crashed on a ranch 30 miles north of Roswell. The Roswell Army Air Field (RAAF) issued a statement claiming to have recovered a crashed “flying disk.” Since then, our celestial cousins and their sweet spacecrafts have been featured in countless films.