I don't care if playing the N.L. East is more economical for the A.L. East as far as travel costs go. Oriole fans don't want to see the Braves, Expos, Phillies, Mets and Marlins year after year without seeing the Rockies, Diamondbacks, Giants, etc. Let baseball fans see McGwire take aim at the Green Monster at Fenway. Let N.L. fans in the Central and Pacific time zones see Cal Ripken play. Let A.L. fans in the Central and Eastern time zones see Tony Gwynn and Barry Bonds play.
Some teams travel to opposite coasts four times a year while others only travel cross-country twice.
So there has to be a way for the Orioles, Yankees and every other team to squeeze in a few games against the Giants or Padres and vice versa. And the rule doesn't have to be that each season one certain A.L. division must play a certain N.L. division. One year, the Orioles can play the Phillies, Brewers, Cardinals, Giants and Astros while the Yankees play the Mets, Expos, Padres, Reds and Pirates. Change it up a little. Make it a little more interesting and unpredictable.