The opening scene of “Way of the Gun,” while not anywhere near 15 minutes, is beautiful. But contains some very rough language, for you people who are at work.
Once Upon A Time in the West is my usual answer for this question. Closer to ten minutes rather than fifteen, but close enough.
The first 15 minutes or so of 28 weeks later are the most tense and terrifying of any zombie movie, the rest of the movie sucks though.
Days of Heaven. The entire film is visually magnificent.
The first FIVE minutes of Disney’s 2000 CGI film Dinosaur are Magnificent. A recreation of a Mesozoic world, marred only by the slight cartooniness of the Iguanodon mom. everything else was superb – magnificent vistas of herds of dinosaurs, various creatures depicted in everyday life as the stolen egg migrates through the scene. the sweeping shots of the flying pterosaur. And none of the dinosaurs speak or are otherwise anthropomorphized.
Of course, they couldn’t keep it up. They have to have speaking characters so they can interact. They throw in thoroughly out-of-period lemurlike mammals. The meteor crash that precipitates the action is obviously not the Chicxulub event that wiped out the dinosaurs, but some much lesser and more local event, etc. etc.
But — Man! – those opening five minutes (which played as a trailer in early 2000 for the film). That was something special.
Another great – the title sequence of the Orson Welles movie Touch of Evil, with thev time bomb in the trunk of the car going through customs.
I’ll also nominate the opening of the Fred Zinneman film Day of the Jackal, based on the Fredrick Forsyth thriller. Ignore completely the awful remake.
Something compelled me.
Raiders of the Lost Ark.
I don’t think it’s a full 15 minutes long, but the opening scene of The Lion King was amazing when it first came out.
Enemy at the Gates.
Stukas dive bombing Russian boats carrying ill equipped Russian soldiers across the Volga. One gun, two ammo clips for every two soldiers in a forced suicide assault on the German line. And then the shooting exploits of Vasily Zaytsev.
Always loved the opening to Tarantino’s From Dusk til Dawn.
Speaking of opening sequences from Disney films that were used as a trailer - you have to count the opening of The Lion King, as a classic example of a WOW! moment.
Phantom of the Opera had a very visually appealing opening 15 minutes.
Scream. So unexpected and shocking.
The beginning of Inglourious Basterds is probably my favorite scene from any Tarantino film.
The opening cartoon of Who Framed Roger Rabbit?
Agree with the two cites for Lion King, and there were some other good examples. Another one, though again it doesn’t qualify for a full 15 minutes, was the opening credits of Life of Pi. Exquisitely filmed visuals and a beautiful soundtrack.
Pulp Fiction. “I’m sorry, did I break your concentration? You’re finished? Then allow me to retort. What does Marcellus Wallace look like?” Everything up to that, from the diner scene to Jules and Vincent discussing foot massage technique, tells you this is going to be an odd film driven by dialogue.
Citizen Kane
The long LONG pan shot that opens Gravity. It shows right then and there that Cuaron is trying something unique this time.
It’s only three minutes but it’s an awesome three minutes…
Pulling away from Earth as the radio signals get older and older until there’s nothing because humans hadn’t yet invented radio.
It’s really hard to determine whether the openings I remember are actually around 15 minutes.
Two not mentioned:
Baz Luhrmann’s Moulin Rouge. I think the frenetic first ~19-21 minutes are quite interesting. Then it lulls.
The Firefly movie Serenity had a nice opening. Really nice action, snappy dialogue, etc. Then after they crash landed … umm, did somebody stop writing this thing? An entirely different movie from then on. And not in a good way.