Because it's all but impossible to rank these, we'll go in chronological order. These are the top 10 trades of the last five seasons (2011-16) that looked OK at the time and now, they do not.
July 30, 2011 -- Chris Davis and Tommy Hunter traded by Rangers to Orioles for Koji Uehara
Maybe this doesn't seem so lopsided now, because Uehara was pretty good in just more than a year with the Rangers, contributing 54 innings of 2.50 ERA ball, striking out 66. That said, he faced a total of 199 hitters in the regular season with Texas, so his total impact was limited. Meanwhile, Davis, who was well into his fourth season of showing big power and a huge inability to make enough contact to make use of said power, broke out with Baltimore, hitting 161 homers with a .257/.339/.523 (132 wRC+, where 100 is league average) before he became a free agent following 2015. (Yes, he re-signed, but that's separate from what Baltimore acquired in the deal.) Hunter, it should be noted, gave the O's 400 innings of league-average performance.
Dec. 8, 2011 -- DJ LeMahieu and Tyler Colvin traded by Cubs to Rockies for Ian Stewart and Casey Weathers
The Cubs needed a third baseman to replace the departing Aramis Ramirez, and thought Stewart, who hit 43 homers in 2009-10 with Colorado before collapsing in 2011, might be a good change-of-scenery gamble. It didn't work. In one year with the Cubs, he hit .201/.292/.335 (66 wRC+) in 202 plate appearances. LeMahieu, on the other hand, was a lightly regarded prospect who gave the Rockies more than three years of plus defense at second base before breaking out in a huge way in 2016, hitting .348/.416/.495 (128 wRC+). He's still under team control for two more years.
Jan. 6, 2012 -- Anthony Rizzo and Zach Cates traded by Padres to Cubs for Andrew Cashner and Kyung-Min Na
It's easy to argue that San Diego gave up on Rizzo too quickly after a poor .141/.281/.242 (59 wRC+) debut in his age-21 season, and they did. That said, the Padres had just acquired first-base prospect Yonder Alonso from Cincinnati, and Cashner was a highly regarded flamethrower who managed to give the team three roughly average seasons, but he never came close to reaching his potential, in part due to injuries. Rizzo, of course, has become a legitimate superstar, easily one of the four best first basemen in the game. This might have been the deal that jump-started the "new" Cubs.
July 31, 2012 -- Kyle Hendricks and Christian Villanueva traded by Rangers to Cubs for Ryan Dempster
LeMahieu aside, the Cubs quietly making very good trades is about to become a recurring theme. Dempster famously decided to accept a trade to Texas rather than the Dodgers minutes before the Trade Deadline, and he gave the Rangers a dozen starts of 5.09 ERA ball. Hendricks was viewed at the time as a Class A pitcher "who may not have the highest ceiling" but "could move quickly and help the back end of a rotation in the future." Well, that and then some; his 2.13 ERA helped him finish third in NL Cy Young voting. He's just entering his age-27 season.
Dec. 17, 2012 -- Noah Syndergaard, Travis d'Arnaud, John Buck and Wuilmer Becerra traded by Blue Jays to Mets for R.A. Dickey, Mike Nickeas and Josh Thole
You know why this looks bad for Toronto now, because Syndergaard is proving himself to be an elite ace, and he's only 24. But remember what it looked like at the time, because Dickey was fresh off a Cy Young Award, his third straight good season, and the Blue Jays, who had just completed the big Jose Reyes/Mark Buehrle trade, were in full "go for it" mode. It was d'Arnaud, not Syndergaard, who was actually viewed as the jewel of the trade, and that hasn't worked out so well. There were plenty of Mets fans more upset about this at the time than were Jays fans. We're guessing that's no longer true.
July 2, 2013 -- Jake Arrieta and Pedro Strop traded by Orioles to Cubs for Steve Clevenger and Scott Feldman
This might end up as one of the most lopsided deals in history, not only because Arrieta has become a top ace, but because Strop has become very good as well, whiffing 254 hitters in 211 innings for Chicago. When it was made, though, Arrieta was a struggling 27-year-old who had a 5.46 ERA in parts of four seasons with the Orioles, and the Cubs sent him to Triple-A for more than a month after acquiring him. As it was reported at the time, the impetus of the deal for the Cubs more than anything was simply acquiring some of Baltimore's international signing money.
Dec. 10, 2013 -- Adam Eaton acquired by White Sox for Hector Santiago and Brandon Jacobs as part of three-way deal with Angels and D-backs
Before this offseason's Eaton trade, there was this one. After two seasons of part-time play in the desert, Arizona traded Eaton to Chicago in part of a three-way deal that also netted them Mark Trumbo and cost them Tyler Skaggs. That didn't work out so well for the D-backs, but it worked out extremely well for the White Sox, who got three years of very good play from Eaton (.290/.362/.422, 117 wRC+, 12.8 WAR) in exchange for a prospect who never made it in Jacobs, and a pitcher they didn't really miss in Santiago. Eaton's value, of course, was extended further when he was traded to Washington this winter in a deal that netted Chicago top prospect Lucas Giolito and two others.
July 5, 2014 -- Addison Russell, Dan Straily and Billy McKinney traded by Athletics to Cubs for Jason Hammel and Jeff Samardzija
At the time, baseball's best team was the 2014 A's, who were correct to see that their rotation was collapsing. Though the move didn't stem that collapse, they were later able to flip Samardzija to the White Sox for shortstop Marcus Semien, who hit 27 homers with improved defense in 2016. This made sense for both sides at the time, though the Cubs look great right now, because Russell looks like he'll be a star.
Dec 8, 2014 -- Yasmani Grandal, Joe Wieland and Zach Eflin traded by Padres to Dodgers for Matt Kemp, Tim Federowicz and cash
It's easy to see Kemp's 35 homers and Grandal's .228 batting average in 2016 and assume the Dodgers got fleeced, but that's simply not how baseball works any longer. Batting average isn't valued; on-base, slugging, defense and framing are. Grandal and Buster Posey have been baseball's two best framing catchers the last two years, and they've also been baseball's two best-hitting catchers. Despite Kemp's power, he's been one of the lowest-rated defenders in the game, and San Diego ended up being so eager to move him that they traded him to Atlanta for nothing more than the toxic contract of Hector Olivera, who never played a game for the Padres. Los Angeles also saved $75 million in this deal. It's a slam-dunk steal for the Dodgers, even if many can't see it.
Dec. 2, 2015 -- Trumbo and C.J. Riefenhauser traded by Mariners to Orioles for Clevenger
Our final trade is the second appearance for both Trumbo and Clevenger, and the fact that Dan Duquette picked up 47 homers and a relief prospect for the mere cost of a third-string catcher the Orioles didn't need is an easy slam-dunk win for Baltimore, especially if Trumbo signs elsewhere and they get a Draft pick out of it, too.