30. Phil Simms
Sports Illustrated once called Phil Simms the most underrated NFL quarterback of all time, and it's a fair argument. Even with the career of Eli Manning, who has broken nearly all of Simms' team records, many still consider him the greatest passer in New York Giants history.
Simms led the Giants to two Super Bowl wins but only went to two Pro Bowls and was an All-Pro selection just once. Even if his yearly stats weren't too astounding — he only topped 4,000 passing yards once and never surpassed 22 touchdowns — his performance in 1987's Super Bowl XXI is the stuff of legend. He completed 88 percent of his passes (22 of 25) and had a passer rating of 150.9, arguably the best performance by any QB in Super Bowl history.