Evasion tanking.

Damage reflection tanking.

Damage absorption tanking.

DoT focused melee class.

HoT based healer.

DPS/Healer/Tank built around building stacks of a buff or a debuff then doing a move that consumes it for a finishing move.

Ranged weapon tank (i.e. a tank class with heavy armor and cooldowns that uses a ranged weapon).

Support melee dps.