Assassinate xp works out well. Hit Plane of Fire at your lvl and stock up on some AA. It's too easy to not AA front load there.
Train Rogues Fury
Learn Counter Attack
Then use them in tandem and test your limits.
Thank you for your response. A guildy pl'd me to 75 today and I have like 2 ranks of assassinate, and Knaves Return Strike for the riposte back stab.
My next AA's that I think I think I will max but not in this order are:
Knaves Return Strike
I understand at 75 I can Assassinate in HoH as well. Maybe I will alternate with that and Fire, or when Fire is being swarming or headshotted.