I havent seen tons of documentaries and I honestly dont know if Ive ever sat down to watch a foreign one. If you guys think there are one or two off your list that are a must see please let me know and I will at least put it in my Netflix que. Here are some documentaries that I can think of that I have seen and liked. The ones I like the best are listed towards the top as the more political ones can be depressing.

Baraka 
March of the Penguins
Joseph Campbell and the Power of Myth
The Living Sea
Coral Reef Adventure
Rivers and Tides
Black Holes: The Other Side of Infinity
The IMAX Space Collection:
The Blue Planet
Mission to Mir
The Dream is Alive
Hail Columbia
Destiny in Space
Capturing the Friedmans
The Fog of War
Startup.com
Roger and Me
The Corporation
Outfoxed