Stalemates in History - The Longest Game to End in a Stalemate

An intentional stalemate occurred on the 124th move of the fifth game of the 1978 World Championship match between Anatoly Karpov and Viktor Korchnoi. The game had been a theoretical draw for many moves (Karolyi & Aplin 2007:170), (Griffiths 1993:43-46). (Even if White wins the black pawn, the black king can get to the a8 corner and set up a fortress. However the players were not on speaking terms so neither would offer a draw by agreement. Korchnoi said that it gave him pleasure to stalemate Karpov and that it was slightly humiliating (Kasparov 2006:120). (Incidentally, as of 2008 this is the longest game played in a World Chess Championship final match, and also the only World Championship game to end in stalemate (Fox & James 1993:236).)

information combined from wikipedia and chessgames.com