No. 3 – Harold Reynolds
Harold Reynolds was the first really good and consistently good Mariners second baseman. Between 1987 and 1992 Reynolds rarely missed a game for Seattle. He appeared in two All-Star games and won three Gold Gloves.
He also led the majors in stolen bases with 60 in 1987, hit .300 in 1989, scored 100 runs in 1990, and led the majors with 11 triples in 1988. Reynolds was good in lots of different ways for Seattle.
Reynolds never had a negative defensive WAR with Seattle and had a defensive WAR of 2.6 alone in 1990. This means even if Reynolds had never stepped up to bat for Seattle he would still have won Seattle nearly three games just by playing in the field.
If Reynolds were a young player on the 2021 Mariners team, he would be a nearly perfect fit for what Seattle wants to do. Heck, Seattle might have made the playoffs in 2020 if Reynolds had been their second baseman.
Reynolds finished the last two years of his career away from Seattle but they will not be memorable. What will be for Mariners fans is his time as a Mariner and then for major league baseball fans as an analyst on ESPN for the last 3,564 years.