Not a huge fan of documentaries, but went with a bunch of college age kids to see
http://buy.soundcitymovie.com/ a couple of weeks ago.
Rocker Dave Grohl did a documentary about Sound City Studios out in California. The studios were one of the most famous analog recording studios that ever existed. Tons of famous stars recorded albums there. Besides having a perfect sounding studio, they had this monster soundboard. When the studio closed, Dave Grohl bought the soundboard and had it re-installed in his own studio. There, he recorded a new album with lots of the stars that had originally recorded at Sound City (Stevie Nicks, Rick Springfield, and even Sir Paul McCartney, etc.).
If you love music, especialy classic rock, then it's a good look see. I want to buy the resulting CD...