Not necessarily a movie you're a great fan of, but with an intro that sets up the tone and atmosphere perfectly, maybe introducing main characters. An intro which makes you want to immerse yourself in the movie's universe.
My choice is The Goonies. Not my favourite movie by a long shot but I find the intro perfect, containing all the elements mentioned above, and what a soundtrack!
I really have to watch Freddy's Revenge again very soon. It deserves more praise than it got. I don't remember the intro - could you please elaborate, HodWatt?
Lord of War - this was the first one to spring to mind. The bullet's "journey" is powerful stuff.
Touch of Evil - popped in second for obvious reasons.
Rear Window - sets up every theme, every inch of the main character's foolish tenacity, and all the backstory you need in one panning sweep of a room.
Star Wars - John Williams and text crawl for an unforgettable opening kick.
Annie Hall - simple, direct, personal, beautiful.
Monty Python and the Holy Grail - these guys can't make it through an opening credit sequence without diving into the absurd.
Monty Python's The Meaning of Life - a fake movie about accountancy pirates.
And, does the opening credits (The Times They Are A-Changin') from Watchmen count? It's not really the "intro" (that's technically the fight in the Comedian's apartment), but it feels intro-like. If it counts, yeah, throw that one on there, too.
Those are indeed good picks, Ace, and you are free to chose Touch of Evil as no one else has mentioned it yet - probably because of my preemptive scolding ;-)
I especially agree about the Watchmen intro btw, it's absolutely poetic, and I've never seen anything like it before! It reminds me to do another thread about favorite end credits (where my first pick would be Captain America: The First Avenger).
Ah, especially Temple of Doom! I love how the cabaret dancing blends into Indy walking down the stairs in his white tux. All leading up to this perfect line: ... I suggest you give me what you owe, or "anything goes"! π
Best intro of recent memory I think is Avengers: Age of Ultron. Say whatever you want about the movie (hint: it was pretty bad), but the opening scene... man, that was EPIC!