That's a great question, and I'd say either Jack Nicholson (if he were a couple decades younger) but most likely Johnny Depp. He's one of my favorite actors of all time, if not my absolute favorite. He's so creative and down to earth, it's unreal. I'd really like to see him and Night make a film together. And, this might sound ironic, but for a female lead my first person considered would be Zooey Deschanel. When I heard she was cast in The Happening early last year, I had never seen a single film of hers and decided to look her up and see what to expect, then I got completely hooked on her. She's now my favorite actress, which makes me that much more excited for The Happening.
The only reason I ask this question is because I actually did it a little after Signs came out: Have you ever attempted to make a crop circle?