Hearts of Iron 2 is the most impressive game I've ever seen, but the AI just can't keep up. Maybe the Doomsday version is better, but the game just seems too easy - last game I played as Italy I had sunk the entire British fleet by 1940. I literally didn't know what to do next - invade Britain? LOL. Didn't seem very realistic, let's just say. Though it was fun taking Gibraltar, the Suez, Malta and Crete. I'll try Doomsday and/or one of the historical mods soon, see if it is any better. But I'd have to say my all time favorite strategy game is MOOII.