Joe Montana had a preternatural understanding of the entire field- I can't count the number of times he'd drop back in the pocket, scan the field and sidestep a rusher coming from behind him to deliver the ball right on target. He seemed to have eyes in the back of his head. He was incredibly accurate and completely unflappable- truly he had icewater running thru his veins. When the pressure what on, there's no QB I'd rather have running my 2 minute drill than Joe Montana in his prime.
Well, if there is another one it's Tom Brady. He has that same incredible poise and calm that Joe had. Funny, growing up Brady idolized Montana, then he grew up to possess as much of Joe's talents than any other QB I can name. He has great awareness of the field, too. It doesn't matter who he throws to, he doesn't seem to have or need a favorite target.