The Bear Totem Barbarian is the undisputed tank in 5e. Especially if you're a Goliath or Half-Orc. My Goliath Bear Barb was damn near impossible to bring down. There were a few times that by the time resistance + Stone's endurance were factored in, he took almost no damage from massive spells that completely KOed other characters. (namely the Sorcerer)
My Vhuman Tempest Cleric with Heavy Armor Mastery was extremely tanky. High AC, negating 3 melee damage per hit, and dishing out reaction damage made him a very hard to drop. In fact, that character has never dropped to 0 hp at any time. I imagine a Life Cleric with Heavy Armor Mastery feat would be extra tanky too.
My Vhuman Tempest Cleric with Heavy Armor Mastery was extremely tanky. High AC, negating 3 melee damage per hit, and dishing out reaction damage made him a very hard to drop. In fact, that character has never dropped to 0 hp at any time. I imagine a Life Cleric with Heavy Armor Mastery feat would be extra tanky too.