By worst I also mean best. At least for one team. Reading the Lincecum thread got me thinking about lopsided trades, and one immediately springs to mind:
July 30, 2004, Tampa Bay acquired nonroster LHP Scott Kazmir and RHP Jose Diaz from the Mets for RHP Victor Zambrano and RHP Bartolome Fortunato
Did anyone on the planet think this was a good trade for NY? TB absolutely stole him from NY. They got the Mets to pay the signing bonus and they reap the benefits. Oh what should have been... but that's another thread.
Is Zambrano still in the majors at this point?