I was just there myself. Glad you included the Soviet War Memorial, it's particularly interesting I think as it's on the west side of town, constructed in a big hurry before the city was divided. I always thought this was a trick by the Soviets, but after some more research I'm inclined to believe all the allies were pretty cooperative about it.

Another site for the war buffs and those who like to get off the tourist path is the Schwerbelastungskörper, a giant concrete block constructed to test the soil's load bearing capability for giant Nazi buildings to be constructed after Germany's planned victory. It's still in use to some extent, but also considered to be too close to apartments to disassemble at a reasonable cost.

Anyone going to Berlin should read up on its history, especially the Berlin Airlift; acting as an enclave of the West behind the Iron Curtain for decades has bestowed it with a very special spirit.