You might like Control Room http://www.imdb.com/title/tt0391024/ It's about Al Jazeera.

Taxi to the Dark Side is probably really good http://www.imdb.com/title/tt0854678/ I didn't watch it even though I really wanted to

Several others I planned on watching, but didn't, and now I'm on hiatus from films. Most of them are in the IMDB top 50 http://www.imdb.com/chart/documentary