Iron Qon from the normals.
Probably Tortos from the heroics i've done so far, really looking forward to Durumu.
The fights this tier have been pretty innovative, but none have really dazzled me, hopefully that will change when we see some of the later fights on Heroic - Dark Animus, Iron Qon, Twin Consorts, Lei Shen and Ra-den
Hoping it will be Ra-den!