I know mythic wz on the weekends affords easy access to camo and radar boost (name) but without that, where do you assassination champs like to .... clean?
Warzone and Warzone Assault, I have more than 1,700 assassinations ;)

I don't like to use camo or boosts, also the power weapons or vehicles are not my thing, I just use loadout weapons xD
Warzone is where i'll get the most assassinations.
Warzone is definitvly the best place.
I have to say Warzone is the place with the most opportunities to perform the assassinations.
War zone assault two teams of twelve invisiblity power ups my play ground for assasinations
Definitely Warzone. Many more opportunities to pounce on unsuspecting enemies.
Less chance of being interrupted on WZ