3) J.D. Martinez
The Mets could absolutely use another bat. The team ranked 20th in runs scored and saw inconsistent seasons from just about everyone up and down the lineup. Adding a force like J.D. Martinez this offseason to DH would add some stability into a lineup that needs it.
It looked like the former Red Sox DH was on the decline before doing what so many players do with the Dodgers, bounce back. He slashed .271/.321/.572 with 33 home runs and 103 RBI in 113 games. He made his sixth all-star team and was a fixture in the middle of their order behind Mookie Betts, Freddie Freeman, and Will Smith.
Martinez reasserted himself as one of the best designated hitters in the game, but is only a DH and just turned 36 years old. These two factors mean he's likely to get a short-term deal and the AAV won't be astronomical due to his limitations.
Both Daniel Vogelbach and Mark Vientos showed flashes down the stretch for the Mets, but neither showed enough to be handed full-time DH duties. The spot is open for J.D. to take, and if the Mets don't land Shohei Ohtani, I wouldn't be shocked to see them pursue Martinez in free agency.