Set By: John Isner (USA) and Nicolas Mahut (France)
They'll always have Wimbledon. While neither Isner nor Mahut has gone on to do much of anything in tennis, their epic 70-to-68 fifth set tiebreaker is one of the all-time craziest things to happen on a tennis court. The fifth set lasted longer than the previous record holder for longest match in tennis history. While it seems that at some point a longer match will be played just by the laws of random probability, that's sort of like saying at some point you could flip a coin and have it land on heads 100 times in a row. Sure, it will happen eventually, but don't hold your breath.