Starting off the list strong is Carl Pavano, whose name even today makes Yankees fans cringe. When the Yankees signed Pavano to a four-year deal worth just shy of $40 million back before the 2005 season, he was coming off a two-plus season stretch with the Marlins where he was a reliable innings eater, and finished in the top six in Cy Young voting in 2004 when he posted a 3.00 ERA in 222.1 innings of work.
Unfortunately, his time with the Yankees was not remotely as fruitful. In addition to just being bad with a 5.00 ERA in 26 starts from 2005-2008, he was constantly hurt, and some of those injuries were fairly dubious. Pavano missed the 2006 season with shoulder issues (probably legit), a bruised butt, and broken ribs he sustained from a car accident which he didn't tell the Yankees about until the day they were going to activate him from a different IL stint. He then had Tommy John surgery and suffered other "interesting" ailments that pointed to him just not being interested in pitching for the Yankees. He just wanted to cash his checks. Good riddance.
This is a fun one, because Jack McDowell only spent one season with the Yankees after being traded there by the White Sox, where he was a perennial Cy Young candidate. McDowell actually wasn't even that bad for the Yankees, as he posted a 3.93 ERA in 217.2 innings. Sure, it wasn't great and definitely was not what New York was hoping for when they traded for him, but the production was fine.
However, what DOES get McDowell on the list was his relationship with Yankees fans, specifically when he flipped off the Yankees' faithful after he was pulled from a game in the middle of the 1995 season. When you combine that with McDowell being on the mound when the Mariners bounced the Yankees from the 1995 ALDS, you have a recipe for all-time infamy amongst Yankees fans.
Acquiring Jacoby Ellsbury had the recipe for being absolutely amazing, as it is always nice to take a really strong player away from the Red Sox. Ellsbury was coming off a seven-year stretch with Boston where he slashed .297/.350/.439 with 241 stolen bases. Naturally, New York was happy to hand him a seven-year, $153 million deal to bring him into the fold.
Unfortunately, Ellsbury's time with the Yankees would not live up to his billing, as he put up a .264/.330/.386 line in 520 games with New York. Injuries took a toll on Ellsbury's production and sapped his speed, which was was arguably his best tool. Hip surgery in 2018 to repair a torn labrum was the nail in the coffin for his career. This one is kinda sad, because Ellsbury's body just didn't cooperate with him, but it still doesn't make his contract any less onerous in the franchise's illustrious history of giving out onerous deals.