http://www.empireonline.com/movies/features/best-movies/I've always found the movies hard to separate, so I find it pretty accurate to have them side by side in the list. Could easily swap the two around and I'd have no complaints either.
No other Alien film in the franchise.
James Cameron has 4 films in the top 100; Aliens, Terminator 2, Terminator and Titanic (in that order) to Ridley Scott's 3; Alien, Blade Runner and Gladiator (I'm that order).
Predator in at number 87