Brady has 3 times the number of Super Bowl wins as the next closest guy and 2.5 times the number of Super Bowl appearances. He's lapped his field of contemporaries more that twice.
Tom Brady: 6 SB wins in 9 appearances (10th TBD)
Peyton Manning: 2 SB wins in 4 appearances
Roethlisberger: 2 SB wins in 3 appearances
Eli Manning: 2 SB wins in 2 appearances
Warner: 1 SB win in 2 appearances
Wilson: 1 SB win in 2 appearances
Brees: 1 SB win in 1 appearance
Rodgers: 1SB win in 1 appearance
Montana's comparables are a bit tougher because his competing QBs didn't completely overlap his career like Brady's. His early career overlapped with tail end of Bradshaw's career (4 wins for 4 appearances), Plunkett (2 for 2), Theismann (1 for 2) and his late career overlapped with Elway (2 for 5 but 0 for 3 while Montana was playing), Kelly (0 for 4) and Aikman (3 for 3). Montana and Bradshaw stand out as the best of that bunch but the gap between them and their contemporaries isn't as great as the one between Brady's and his.
Pointing out Brady's accomplishments does not diminish Montana's. Both are incredible, but it's not as hard as people are trying to make it.
1. Brady
2. Montana