It doesn't get mentioned as often as it should, but how about Detroit's (read: Jacques Demers bending Jimmy Devellano's ear) bonehead trade in June, 1989? Do you know the one I'm talking about...?
In 1988-89, the Wings had a moderate setback, sagging to a .500 record, but still finishing 1st in the crappy Norris. Apparently, Demers and Devellano thought they knew what the team needed. So, they send Adam Oates and Paul MacLean to St.Louis. In return, they got veteran Bernie Federko, who was 33 and wanted no part of the Wings.
So, how'd this one shake down?
Federko scored 57 points (-8) and retired. Done.
MacLean immediately had a strong, 36-goal season for St.Louis before retiring prematurely the next year after a rib injury (which, presumably, wouldn't have happened if he'd been in Detroit). Oh, and how about Oates? Oh yeah, he scored another 1221 points, finishing top-10 in scoring seven times and 1st in assists three times. Had a 142-point season for Boston. As late as 2002, he was still scoring at a point-per-game.
I know people can say, "Well, Oates wasn't Oates yet." But actually he was. He'd just scored 78 points in 69 games (90 point pace), with limited PP-time behind 155-point Yzerman.