From Visual Studio - Command to collapse all sections of code? - Stack Overflow:
CTRL + M + O will collapse all.
CTRL + M + L will expand all. (in VS 2013 - Toggle All outlining)
CTRL + M + P will expand all and disable outlining.
CTRL + M + M will collapse/expand the current section.
These options are also in the context menu under Outlining.
I keep forgetting these.