For those looking to stream online, go to topdocumentaryfilms.com . Couple need to watches:
Most hated family in america(bbc special of a guy that got inside access into the Westboro baptist church). Need to see
King of kong. Been mentioned but about a guy trying to break the donkey kong world record. Sounds silly, bits is good
The cove- dolphins slaughtered for meat I Japan.
Hoop dreams is good, but dated. Interesting seeing that side of inner city kids trying to get bball scollys
These are just a few I can think I watched recently. The site I mentioned earlier is amazing for watching every kind of doc you are looking for.
once brothers is pry one of the best ones i have seen. it was a 30 on 30 film