Great thread!
1) Nap Lajoie hitting for the cycle with a grand slam on July 30, 1901 in the inaugural year of American League when he won the triple crown and hit .426
2) Oscar Charleston facing Walter Johnson in an exhibition game (date unknown)
3) Babe Ruth's called shot Oct. 1, 1932 in Game 3 of Wor Series at Wrigley Field.
4) Josh Gibson's
legendary 600-foot home run that reached the backyard of the Belmar Post office in Belmar, NJ on July 24, 1936.
5) Mets vs. Red Sox in game 6 of World Series on October 26, 1996.
Honorable Mentions:
1) Christy Mathewson gets 3rd shutout in Game 5 to close out World Series vs. Charles "Chief" Bender and the Philadelphia Athletics on October 14th, 1905.
2) Addie Joss' perfect game on Oct. 2 1908 when he outdueled Ed Walsh.
3) Grover Cleveland Alexander's strikeout of Tony Lazzeri with bases loaded and two outs in 7th game of 1926 World Series.
4) Jackie Robinson's first game with Dodgers
5) Game in which Willie Mays caught a ball off Bobby Morgan at Ebbets Field in Sept. '51 in which he dove parallel in the air, hit the wall and knocked himself out. Upon awakening he saw Leo Durocher (who was checking on Mays' health) and Jackie Robinson who had come all the way from the dugout. Mays said that was his best catch ever.