Skepticism and rationality are I believe two of the most important traits a person can possess. However, documentaries can most certainly assist you in gathering information and forming opinion. I don't trust every documentary that's out there, which is one of the reasons I refuse to watch "Loose Change".

Let me elaborate.

I personally dislike extensive reading, it's not that I mind fact checking. If I had the time and motivation I'd do it for each and every one of these documentaries, but actual fact checking is an extremely difficult process. I'm going out on a limb here but assume it's also one of the pillars of good journalism.

I firmly believe that the documentaries I listed have done their fact checking, but I can't make any guarantees.[1] Adam Curtis and Bill Moyers in particular aren't just your average Joe from the corner store, from what I can tell they've earned their credentials. Just take a look at their Wikipedia pages,[2] you'll see that Bill Moyers for example received a Lifetime Emmy award in 2006.

[1] I must admit that in light of the whole situation with Jesse Macbeth we have to be careful about interviews with soldiers such as those presented in "The Ground Truth". Though I did do a quick Google before listing it and nothing was presented to argue that any of the persons interviewed weren't who they were claiming to be.

[2] I know Wikipedia isn't a credible source, but it's usually the best place to start your research from since it bundles information together. Be my guest to fact check any it.