For a truly intense Aliens fix, try out this flash port someone made on Newgrounds of the old Aliens board game. You basically play out the action-packed scenes from the movie, and the game uses the music and sound effects from the film as well, to further enhance the atmosphere. It's quite a challenge, as well!
http://www.newgrounds.com/portal/view/408816http://www.newgrounds.com/portal/view/408816