Some of these are going to hurt to read and some players might even appear on this list a few times *cough* Taylor Hall *cough*
Anaheim Ducks
The worst trade made by the Anaheim Ducks over the past 10 years likely won't be the only one on this list that surrounds the NHL Vegas Expansion Draft. At the time the Ducks valued both Sami Vatanen and Josh Manson very highly, so to protect those two the Ducks opted to strike a deal with Vegas.
The Ducks offered up 21-year old Shea Theodore in exchange for Vegas not selecting Manson or Vatanen. Ultimately losing either Manson or Vatenen would have been the much smarter move. Theodore immediately began to thrive in Vegas and ultimately became the top pairing defenseman that the Ducks are currently lacking.
Theodore has gone on to play 281 games for Vegas while scoring 42 goals and adding 123 assists, while playing 21 plus minutes per night. To say this was a bad move for Bob Murray would be an understatement and I'm sure a move that he'd love the chance to do over.
Arizona Coyotes
The Arizona Coyotes gave us a couple choices to choose from and both the Derek Stepan and Taylor Hall trades both received consideration, but we finally settled on Hall. It became clear Hall had no intention of returning to New Jersey and the Devil's decided to move the former Hart Trophy winner. The Coyotes started off their season with a strong start and wanted to add so naturally there seemed to be a fit.
The deal finally came together December 16th as the Coyotes acquired Taylor Hall and Blake Speers in exchange for Nick Merkleu, Nate Schnarr, Kevin Bahl, a 2020 1st round pick and a 2021 3rd round pick.
Hall went on to score 10 goals and add 17 assists for 27 points in 35 games with the Coyotes, but the team was ousted in the 1st round by the Avalanche bringing Hall's tenure in Arizona to an end. The Coyotes' and Hall couldn't come to an agreement and finally his stay ended closing this chapter on what ended up being a bad deal for Arizona.
Boston Bruins
This trade is less about who the Bruins acquired and more about who they gave up. It sounded like there were some behind the scenes issues and Boston with Seguin and like Phil Kessel and Joe Thornton before him Boston chose to separate themselves from another top pick.
The Bruins sent former 2nd overall pick Tyler Seguin, Rich Peverley and Ryan Button to Dallas in exchange for Matt Fraser, Loui Eriksson, Joe Morrow and Reilly Smith.
Eriksson was never able to replicate the success he had in Dallas and Seguin went on to become a multi-time 80+ point scorer. The Bruins likely don't regret this deal, but it's difficult to believe there wasn't a better deal available to the Bruins at the time.
Buffalo Sabres
This isn't the first or the last time you're going to see Taylor Hall's name on this list. Last season on April 12th leading up to the trade deadline the Buffalo Sabres completed a deal to send Curtis Lazar and Taylor Hall to the Boston Bruins in exchange for what should have been a haul, but the Sabres managed to completely botch the Hall situation.
When the Sabres signed Hall to a 1 year deal with 8 million per season they had their sights set on a playoff spot, but as things often do in Buffalo this move failed. Hall only scored 2 goals in 37 games with the Sabres and the Sabres found themselves sitting last in the NHL looking to recoup assets.
The problem?
The Sabres gave Hall a full no movement clause which handed him all the power. There were reports that Hall only wanted to play in Boston, but he later confirmed that wasn't the case. The return the Sabres returned was lackluster at best and goes down as the worst trade since 2010 for the Sabres.
Depending on how things end with the Jack Eichel surgery there might be a new addition to this list shortly.