Anrei Tarkovsky's Solaris, or maybe Jarmusch's Stranger Than Paradise.

The Big Lebowski.

Lost In Translation

Sorry
I don't talk about fight club

KELLY’S HEROES... all time classic WW2 action-comedy.

I really adore a lot of movies, but for some reason The Great Escape is about all I can think of when answering this question.

My all time favourite film? Tough! But I'd go with Seven Samurai (1954 - Japanese language with English Subtitles B/W 208 minutes) A massive film in every way - an action film, a drama and a work of art with stunning visuals and precise characters - at over three hours it still feels too short!

I have several so, I will narrow it down to movies I periodicaly pull off of my shelf and watch:

1776: While I don't typically care for musicals, I love the way this sticks close (enough) to history to tell the tale of how we became a new nation.

A Christmas Story: this one is just too much fun and we pulled it out every christmas for a long time.

The Mummy (1999): again, a fall favorite and one that is just too much fun not to return to on occasion.

The Alien Series: while my heart is with the first one, I have to pull these out every so often and enjoy the thrill again. I think the series is done well, maybe not masterfully but... well.

If you made me choose just one... I'd have to settle on 1776, though the leg lamp calls to me.

In which genre and which generation?

Drama: Spotlight, maybe Empire of the Sun?
Science-fiction: Contagion, Arrival or Deep Impact.
Science-fiction/horror: Alien, or Get Out, ...
Science-fiction action: Aliens, definitely Pitch Black, or maybe Mad Max
Science-fiction comedy, political/social satire: Starship Troopers.
Action: Die hard.
History (fiction or non-fiction): Master and Commander, Schindler's List. Saving Private Ryan, Gladiator

LOL! You gotta be more specific when asking that question.

Highlander

Artificial Intelligence, hands down!

Oooo...thats a tough one. All time favorite? A Clockwork Orange has a special place in my heart. But I think I have to go with Boondock Saints

It is a tie. Casablanca and Blade Runner

I do not have one... Rather several titles that stand out in the crowd.
The Matrix, What dreams may come, Meet Joe Black, The Green Mile, The Shawshank redemption, Moonrise kingdom, Dark city... These are the ones that come to my mind on first thought.