Crippling Dagger
Scorpion Wire --- This sounds like it might be lots of fun against flag runner or fleeing monks
Siphon Speed -- Great way to catch kitin' foes
Viper's Defense -- Poison's foe
Heart of Shadow -- negates damage but causes random shadow step.
Shadow Refuge -- Great

Also gwonline.net and guru offer different definitions of what shadow refuge actually does. Can anyone clarify actually skill description please.
Anyone thought of any other assassin skills much might work well with a warrior, obviously for PvP.