Summit of Sacrifice - that place from GoW2's final boss, for 2vs2 favour of the gods and 4 players match of champions.
Rhodes - the circle place where you fight the Colossus for the last time in GoW2 (the fight you throw his hand on him and then rip his belly with the Blade of Olympus and enter him), 2vs2 favour of the gods and 4 players MoC.
Hera's Garden - The big and hard puzzle from GoW3, make it a 4vs4 favour of the gods, and 8 players MoC.
I'll try thinking for more, post your ideas too.
GOW1 - Aegean Sea - Hydra
GOW 2 - Rhodes - Under the attack of the Colossus
GOW 1 - Challenge of Hades (where the spiked roller circles around)
GOW 2 - Typhon's Cavern