I think voidwalker is the best for PVP, the nova bombe can easily destroy a hammer of sol titan, ae bladedancer or a stormcaller, that's also the only subclass who have blink. For PVE stormcaller is AWESOME ! But, Voidcaller is really fun to, the Sunsinger subclass is also quite fun, especially because of angel of light but its super is probably the least interesting.