Men of War Assault Squad is the best WW2 real-time tactics game! I've been following this game series ever since the original 'Soldiers Heroes of WW2'. When I tried the demo back then, and realized that you can take the shells out of your broken tank to load a stolen anti-tank gun, and you can scavenge the fallen bodies for weapons and ammunition, and you can take cover behind virtually everything, and you can drive tanks through buldings, I was immediately sold.
This amazing level of detail and authenticity is still present today, and it brings an immense level of control and different tactics that you can use. That comes at the expense of very much micromanagement and almost every key on the keyboard being assigned to some action. That makes it hard for newcomers to pick up, but once you memorized everything, you're going to have a blast.
The multiplayer component is a bit shaky, because it uses an old GameSpy service. That's why I have very high hopes for the upcoming Assault Squad 2, which promises to have full Steam MP integration. The developers have been listening to the community a lot and have published several free updates with lots of new content, so I trust them on this one.