Best all-time, aside from Don Larsen (perfect game in a World Series???? Before expansion?):
Walter Johnson's second consecutive shutout of the Yankees/Highlanders. That is, second consecutive game, both CG shutouts by Johnson. Friday and Saturday. (They had Sunday off, so Johnson shut them out on Monday, too.) September, 1908.
Come to think of it, how about the Harvey Haddix 12-inning perfect game that he lost in the 13th? Pirates / Braves, 1959. Box score at:
http://www.baseball-almanac.com/boxscore/05261959.shtml