If you haven't seen it yet, his most recent show on the Discovery channel is incredible. It includes a lot from his previous writings but some new stuff too and it's all set to pretty stunning effects and a great soundtrack reminiscent of scifi movies from the 70s and 80s. You can check it out here:

http://dsc.discovery.com/tv/stephen-hawking/

and the whole series is on netflix. It's truly amazing. Don't miss it.