And the stadium where they'll both play isn't scheduled to open until the 2010 season.
The Giants moved from eighth to fourth in the rankings released Wednesday, valued at $1.178 billion, behind Dallas ($1.612 billion), Washington ($1.538 billion) and New England ($1.324 billion), the perennial leaders. The Jets are right behind them in fifth with a value of $1.178 billion.
Indianapolis made the biggest jump in the rankings, going from 21st to eighth because their new stadium is opening this year. The Colts are valued at $1.076 billion.
The magazine also found that for the first time in any sport, team values averaged $1 billion. Ten years ago, when it first started keeping track, the average value of an NFL team was $288 million.
Forbes attributes the increase primarily to new stadiums as well as increased sponsorship deals.
In all, 19 teams were valued at more than $1 billion.
The value for the top teams also correlates more than in the past with success on the field.
The Giants are the reigning Super Bowl champions; the Colts won in 2007; Baltimore won in 2001; the Patriots have won three titles this decade; the Bears and Eagles have played in recent Super Bowls; and Dallas had the NFC's best record last season at 13-3.