2) NY Mets traded fan favorite Bud Harrelson to the Phillies
The least consequential trade on this list, the Mets sent longtime Mets second baseman Bud Harrelson to the Phillies in March of 1978. In a part a leftover move for the organization to make as they turned the page on the decade, the team received Fred Andrew and cash from Philadelphia in this move.
Harrelson's best days were long over at the time of the deal. He batted just .178 for the 1977 Mets. He wasn't much better with the Phillies either, at least not when he hit .214 for them in 1978.
Harrelson's second year with the Phillies was far more productive yet limited. He received only 87 plate appearances but delivered a .282 batting average in those chances. Unfortunately, he played his final season in 1980 with the Texas Rangers. He wouldn't get himself a second World Series ring like McGraw.
As for Andrews, he spent all of 1978 in the minor leagues. It was his last year in professional baseball. The Mets didn't get much out of this deal at all other than the money and a few disgruntled fans who got to see Harrelson go behind enemy lines for parts of two seasons.
Fortunately, this deal didn't hurt the Mets much. The same isn't true for this next trade.