Super bowl XXI (21).
Super Bowl XXXV to the Baltimore Ravens in 2001.
Super bowl 35.
The Denver Broncos lost Super Bowl XXI to the New York Giants 39-20, on January 25, 1987.
On January 25, 1987, the Denver Broncos were defeated by the New York Giants, 39-20, in Super Bowl XXI at the Rose Bowl in Pasadena, California.
Baltimore Ravens 34-7
Both of his Super Bowl losses have been against the Giants (in Super Bowls 42 and 46)
2011/2012 in super bowl 46 or XLVI
Chicago bears, Green Bay packers, and twice to the New York giants.
In the 2007 Super Bowl, or Super Bowl XLII, the Patriots suffered their only loss of the season to the New York Giants, 17-14.
They lost to the Baltimore Ravens in 2000 Super Bowl 34-7