I'm a big fan of the Stripped documentary. (About comic strips! Get your mind right.) You ought to buy a copy yourself, it's well worth watching. But if you really like comics, then you can also splurge for the extra features, the best of which are the extended interviews with a lot of the cartoonists. It's fascinating to hear all the different perspectives about comics, where it's going, and what it's all about. Check out the trailer here.