Number 42 is retired across all of baseball to honor Jackie Robinson. Because of this, only 13 players have ever worn number 42 in Los Angeles Angels franchise history. This makes choosing the best player to wear it difficult, or easy because of the lack of competition.
Mo Vaughn is the best player to wear number 42 in Angels history
As much as Angels fans don't want to see it, and as much as I don't want to say it, Mo Vaughn is the best Angel to wear this number. His contract was an absolute disaster. He didn't come close to the lofty expectations that came with signing the biggest contract in MLB history. He did, however, have two productive seasons here.
Vaughn's first season with the Halos came in 1999, and saw him slash .281/.358/.508 with 33 home runs and 108 RBI. Those aren't quite MVP numbers like he was posting consistently with Boston, but it's hard to complain about that production.
The 2000 season was more of the same, as Vaughn slashed .272/.365/.498 with 36 home runs and 117 RBI. He led the league in strikeouts and wasn't in the MVP conversation but like those are really good numbers.
It all went downhill for Vaughn after that as he dealt with injury and weight issues, and was inevitably a New York Met in 2002.
The contract was an absolute disaster and one the Angels wish they could have back. The lack of competition for this number is why Vaughn is the best to wear it and with it universally retired, it'll be that way forever.