What is the most intense, close, competitive series you have witnessed on the mainstage?

For me it has to be MLG Orlando 2010 it was Str8 Rippin vs Carbon in the LB and it went to 5 games and every game was so close especially when Str8 won Construct KOTH by seconds all of Str8 was going crazy it was awesome seeing my team win like that until they met up with SQ -_- But anyways how about you?

-And if you haven't been to a tournament then posting up a series from the live stream that gave you the chills is fine too.