Seven Pounds opening scene was pretty fucked up [video=youtube;OyO7pu4KJW8]http://www.youtube.com/watch?v=OyO7pu4KJW8[/video]
I'd also like to throw out the opening to 28 Days Later. It's one of my favorite movies and I love the opening of the movie explaining the virus and what not.
The opening to Watchmen was really well done too. Not just the scene where the Comedian dies, but also when they shows the credits overtop a summary of how history changed with superheroes in the mix.
The long shot at the beginning of Terminator: Salvation is pretty great, very well done. Especially the helicopter parts.