I really enjoyed this movie. It was edgy without being sociopath. Vin Diesel brought the Riddick character to life and made you feel good and bad about him on different levels.
I also saw Iron Giant and Vin is perfect. (The snowmobile movie - oh yeah, it's called "Triple-X," or "xXx" - was a weak example of his work.) In Pitch Black he plays an anti-hero to the max. I don't think you can go wrong when Vin stars in a movie. Unfortunately, Hollowood might type cast him as an adventure action movie star - wrong! I think the script for "XXX" was weak for which Vin couldn't act down to it.
Anyway, Pitch Black is a great scifi - see it!
-Zafoid