Thank you JonGrafto for making an excellent counterpoint: yes, the fact that Brady's teams haven't had a significant rushing attack, aside from a couple of notable years, has forced him to throw more often, which has forced him to _attempt_ more throws than quarterbacks in previous eras, or than some quarterbacks in other teams in the modern era.
But if the guy performed at his position at, just to throw out a name here, the level of a guy like Mark Sanchez, he would never have ammassed the stats he has ammassed. Yes, he may have ammassed the number of attempts, in his first couple of seasons, before his coaches ran him out of town on a rail and found a different approach. And thus, his stats would paint a VERY different picture.
But the fact is that he is indeed an exceptional quarterback, and despite the fact that he does have the occasional gut-wrenching, make-every-New-England-fan-want-to-cry-out-in-anguish, WAY sub par game (like guys like Montana did, thanks for pointing those ones out Cape - these guys are only human), there's no way you're ever going to argue with any sane individual that he doesn't belong in the top 5, and no way you're going to argue with most that he's not in the top 2 or 3.