Duelist: Raze - always has been for me cause she has 4 abilities that do damage, every ability can kill an enemy or do damage at least.
Sentinel: Sage - although she was nerfed, she is still the best sentinel in the game for me, you can make situations from 2v1 to 2v2, you can slow a rush into the site and the wall can be used as defensive wall or attacking wall.
Initiator: Skye - You can clear the whole site with the dog ability, and even when you flash if there is an enemy, you know you flashed him cause of the voice BLINDED.
Controller: Astra - 5 smokes in a round, you can pull out enemies from the corners and even stun them and make them vulnabrle. I personally dont like the ult but can be used for retakes and postplants