Well I'm sure you've worked it out already ... my favourite movie of all time is Aliens (no not Alien, like all the other sci-fi nerds, the sequel).
When I talk with friends and family about the greatest film in history, people think I am taking the piss. Are your serious?, they ask. It's not even the best in the franchise, they say. Blah, blah, blah. Alien (The First) was great, but it was more psychological drama than action sci-fi. Aliens (The Second) was so much better ... and the greatest film OF ALL TIME!
Anyway, that's my humble opinion. It has everything - one of the earliest full-on, tough guy, action hero roles for women (Sigourney Weaver as Ellen Ripley); non-stop action (with a few incredibly tenses, suspense-building interludes; a horrific protagonist (the Alien, especially in its guise as the scariest protective mother ever portrayed); a great little kick at rampant capitalism (as represented by corporation rep Paul Reiser as Carter Burke
"You know Burke, I don't know which species is worse ... you don't see them screwing each other over for a god-damned percentage"); and one of the greatest ensemble casts of supporting actors.
On that note, Private William L Hudson, is one of the funniest supporting characters in the history of movies. Played by Bill Paxton he is constantly coming out with great, whiny one-liners at the perfect time until it is actually "game over" for him at the hands (multiple jaws) of the Aliens.
There are just so many memorable scenes in this movie: The discovery of little Newt; the first chaotic battle; the Alien trap set up by Burke for Newt and Ripley; Ripley gearing up in the elevator as she prepares for her penultimate battle; that crazy 15-minute (in space time) odyssey through a fiery hell; and Ripley and Newt's last stand aboard the mothership Sulaco. Oh my God ... and there are even more, but I am starting to sound like a fan-boy.
And, yes, I know I've revealed some spoilers here, but the movie is bloody-well 35 years old (1986) so if spoilers bother you ... build a bridge and get over it.
No more about Aliens, except to say watch it - over and over again. By the way, it's great viewing with a couple of legacy beers (say Tooheys New, Reschs or even VB), and a large packet of cheese and onion chips. Just to link you in to what the cinema experience was way back in 1986.