Who is the greatest QB of all time?

Johnny Unitas. The only person you can compare is Montana. Unitas was setting records before passing truly became part of the game. He set a record of 47 straight games with at least one passing TD. The closets person since,(which has been about 50 years) is Brett Favre with 36 straight. Not only did he collect stats and MVP's, he was a winner. He won several championships with the Colt's, and went to several others. Je was the best of his day, and would still be the best today.