He's been on the show for all six seasons. There are a lot of Dragons' Den episodes and specials uploaded in high-quality here: http://www.youtube.com/user/DDRepeat
I stopped watching that when Doug Richard left...
(I'm sure the others are great - but uk web investors are the ones I try to obsessivley keep on my radar.)
I've watched quite a few DD episodes. Doug was the most tech-hip Dragon the show has ever had. I think he had the best grasp of, and the most interest in, scalable startups and modern technology. I wouldn't expect the other Dragons to do someday be doing something like this: http://www.schoolforstartups.co.uk Or this: http://trutap.com
I think most people watch it to see a real car crash. When I've watched it, which isn't that often I've been shocked by how bad some of the pitches have been.
Does he do much stuff on the net? startups or such?