The NPD Group released the US PC retail sales for the month of March today and Creative Assembly's Empire: Total War is at the top of the heap. They managed to triumph over the likes of Wrath of the Lich King, The Sims 2, and Dawn of War II. (Empire: Total War, Industry, PC, Warhammer 40,000: Dawn of War 2, World of Warcraft: Wrath of the Lich King)