I found Samurai very tanky. With the ability and high piercing DPS he can do massive damage to a single enemy or group like no other class, so eliminate most threats before they do much damage. The ability and weapon synergise well so you do damage and exposed to whatever is in front of you before finishing them off quickly with your katana while exposed.
The closest is Knight which plays similarly, except you stun before finishing them off. But with most swords not piercing he still needs to finish them off one-by-one, which can take longer with your 50 dex.
The only downside is the ability which is harder to use especially in dungeons. But this makes it more interesting, and it makes it more useful in e.g. shooting round corners or over walls.