T34/85 for sure. Because it comes earlier and can start killing infantry in mid game.
I think all the heavy tanks should be shaped/balanced as IS-2. Heavy to receive some damage, stronger than any other tier tank but not that strong to wipe enemy infantry or tanks.
I would balance Tiger/ISU-152 and Elephant like that tank.
...Who would get then Elefant or ISU152 if they cant do good damage from afar?