For what it's worth, some of the top free agents in 2019 are
Klay, Boogie, Jordan, Kemba, Bledsoe, Tobias Harris, Vucevic, Mirotic (unrestricted)
Kyrie, Butler, Kawhi, Durant, Love, Middleton, Horford, Marc Gasol, Dragic, Teague, Harrison Barnes (player options)
Not included restricted free agents and team options cause if the players are good enough there is practically zero chance they change teams.