The John Williams score, the whip, the silhouette, the spiders, the traps, the boulder chase — no single part of the opening to Spielberg and Lucas' Raiders of the Lost Ark doesn't scream iconic.
The opening to James Cameron's sequel was a feast for the eyes when it was released in 1991, but what makes it remain so powerful is the meticulous mis-en-scene that demonstrates how everything we love could be gone in a literal flash.
This is probably the most tense conversation over a glass of milk ever committed to film. If the opening of Inglourious Basterds were a guitar string, it would be about to pop at any moment.
Never before or since has an opening text crawl filled fans with joy and excitement to see the sequel to one of their favorite films. That fight on Hoth is pretty decent too.