Jerry Grote (1966-1977)
For some guy named Tom Parsons who never played in the majors again, the Mets got an All Star catcher who was able to bring the greatness out of a young pitching staff. Johnny Bench famously said if he and Grote were on the same team, Bench would have to play third base.
Tommie Agee (1968-1972)
The Mets gave up four players to get Agee, the best of whom was Tommy Davis, whose best years were behind him. Agee singlehandedly saved Game 3 of the 1969 World Series. As a bonus, the Mets also got Al Weis, another World Series hero, in the trade.
Keith Hernandez (1983-1989)
For the price of pitchers Neil Allen, who never could harness his talent, and Rick Ownbey, the Mets got the man who led them to the 1986 World Series. Not a bad swap indeed.
Ray Knight (1984-1986)
The Mets sent three players of very little consequence to Houston for Knight, who went on to be the 1986 World Series MVP.
Bob Ojeda (1986-1990)
Ojeda came over to the Mets in an eight player deal with the Red Sox, and proceeded to go 18-5 in 1986. The only player of note the Mets sent away was Calvin Schiraldi, who helped the Mets more as a Red Sox than he ever did as a Met — he was the losing pitcher of Game 6 of the 1986 World Series.
David Cone (1987-1992, 2003)
The Mets got Cone from the Royals for three players, the top one being Ed Hearn. Hearn was actually a very promising young catcher, but injuries and then a very serious disease cut his career short.
John Olerud (1997-1999)
For some reason Olerud fell out of favor with the Blue Jays, and the Mets were able to get him for medicore pitcher Robert Person. And if memory serves me right, Toronto also paid around $6 million of Oleurd’s $6.5 million 1997 salary.
Mike Piazza (1998-2005)
After spending a week in Florida, the Marlins turned around and dealt Piazza to the Mets for three players, the best being Preston Wilson. Wilson had a few good power years, but he was nothing compared to Piazza — the best hitter in Mets history.
Carlos Delgado (2006-2009)
A year after spurning the Mets as a free agent, Omar Minaya finally landed Delgado, sending Mike Jacobs, Yusmeiro Petit and a minor leaguer to Florida. Jacobs had a couple of good years, but now both he and Petit are looking for jobs after being released by their teams.
Johan Santana (2008-Present)
The Mets landed the best pitcher in the game without giving up any of their top prospects. Carlos Gomez could still develop into a good player, but the Twins have already given up on him. Philip Humber has appeared in just 13 games in Minnesota in two seasons, and has not fared well.
Mug Shots Courtesy Ultimate Mets Database, http://ultimatemets.com/mugshots.php