Those are just solid sci-fi movies there. Vin Diesel looks like a meathead, but he's actually a pretty big nerd. He's still a huge D&D player.
Good news, everyone. There's a new Riddick film scheduled to be released in 2013, written and directed by the same guy as the first two.
http://en.wikipedia.org/wiki/Riddick_(film)
That guy, David Twohy, burst onto the Hollywood scene by writing The Fugitive in 1993. His career then took a pretty major step backwards after writing Waterworld in 1995.