What's The Best (Or Worst) Voiceover Monologue At The Start Of A Movie?

Some movies just drop you in the deep end, and let you figure out what's going on. And some movies talk you through it. Opening voiceovers are a major component of science fiction and fantasy movies (see 50 of them here) and they can be wonderful. Or just god-bananas-awful. But what are the best? And the worst?

Please include a clip or still image for your favorite (or least favorite) opening voiceover. And please let us know the name of the movie, and why it's the best or worst. Thanks!

Top image: Terminator 2: Clearly the best. We hear all about the apocalypse before we get plunged into the battle to stop it.