Captain of the Hunt, but I don't have it yet lol
Seasonned Tracker. Cause hunting those S Rank Hunts are a pain in the ass, between the respawn timers lasting for half a week and the requirements themselves to spawn them. I don't see many with that title too
Bounty Hunter & Hunter for hire are a tied third.

Gambler goes nicely with the Gambler's Trenchcoat too, but it's a bit too boring