No. 1 worst contract in LA Angels modern team history: Josh Hamilton (2012)
The LA Angels' worst contract in modern team history has to be Josh Hamilton. Hamilton was signed to a five-year/$125 million deal, and ended up experiencing drug addiction relapse, injuries, and poor baseball performance. The first two are awful, and weren't deserved, so I'll focus on the baseball performance here.
Hamilton played just two years with the Angels before he was back off to Texas, where he played just one year. With the Halos, Hamilton hit .255/.316/.426 (.741 OPS) while he had just hit .304/.364/.549 (.913 OPS) prior to his signing. There was a deep regression, and he also only ended up playing 89 games in his second season with us.
He's another guy who had been an All-Star with his previous team(s) (five times to be exact), and went to the Angels and never was. Hamilton, who hit 43 home runs in the year prior to signing with the Halos, hit just 31 total in his Angels career. He totaled 123 RBIs with the Halos after driving in 128 in the season prior to going to the Angels.
None of these guys panned out how they were supposed to, and it's a major part of why the Angels are where they're at today. Hopefully Minasian doesn't make these mistakes moving forward, and we can finally taste victory again.