Intro's in movies are normally action packed, funny, or give a giant brain teaser that we have to continue watching, and many terrible movies have great intro's while great movies have "meh" intro's.
My list is this: (SPOILERS AHEAD!)
Lord of the Rings: The Two Towers.
Starts out in the PAST bringing us back to one of the most emotional moments in the trilogy, not only showing this great scene with Gandolf fighting the Balrog but also showing it in different camera angles. It continues to answer the question of where Gandolf really went, and how epic of a fight it was! It leaves off making you wonder if he really did survive... Or was it just a dream of Frodo's? Both??!
Transformers: Revenge of the Fallen.
There are lots of bad things that can be said about this movie, but the intro is a true gem IMHO. It opens up with visually one of the most amazing scenes I can remember in Cinema, not only is a giant Crane Decepticon rolling over half the city, we get to see Optimus Prime launch himself out of an airplane and bring the fight to him! This scene instantly got me thinking "WHOA!" when I saw both optimus and the crane literally crash right through the giant bridge, the camera work/special effects/ and action was perfect.
The Dark Knight Rises.
Honestly, how else can you use less than 10 minutes to tell the audience that the main villain is a complete Badass? Not only did Bane make himself very intimidating, but his Theme (thanks Hans Zimmer) beating in the background started to make the hairs on the back of my neck rise. Bane did not simply beat some people up, he managed to complete an objection that others would call impossible. Simple using a bigger plane, couple of henchmen and a cord to hang on too. This guy was fearless and showed us he was willing to do anything to complete his task.
If you have any others, lets hear them!