Baltimore Ravens
The Steelers defeated the Denver Broncos three times in the playoffs.December 30, 1978 (33-10)December 30, 1984 (24-17)January 22, 2006 (34-17)
Dallas Cowboys, Denver Broncos, Kansas City Chiefs, Houston Oilers, and Miami Dolphins.
The Saint Louis Rams defeated the Tennessee Titans, 23-16 in Atlanta, GA in 2000.
They were not in Super Bowl XV. The Oakland Raiders beat the Philadelphia Eagles by 27 points to 10. They played in Super Bowl XL, losing to the Pittsburgh Steelers. They played in Super Bowl XLVIII when they beat the Denver Broncos.
The Washington Redskins beat the Denver Broncos 42-10
The Dallas Cowboys did not play two consecutive losing Super Bowls. However, they were beaten in their two appearances against the Pittsburgh Steelers in Super Bowls X and XIII. Between those two, Dallas beat the Denver Broncos in Super Bowl XII. (Dallas finally beat the Steelers in Super Bowl XXX, but are one victory behind Pittsburgh.)(see the related concise list question)
Yes! NO!
Super Bowl XII - XIIIThe Dallas Cowboys beat the Denver Broncos 27-10 in Super Bowl XII played on January 15, 1978.The Pittsburgh Steelers beat the Dallas Cowboys35-31 in Super Bowl XIII played on January 21, 1979.
The 1971 beat the Miami Dolphins The 1977 team beat the Denver Broncos The 1992 and 1993 teams beat the Buffalo Bills The 1995 team beat the Pittsburgh Steelers. There losses were: 1970 to the Colts 1975 and 1978 to the Steelers
Super Bowl XII -XIVThe Dallas Cowboys beat the Denver Broncos 27-10 in Super Bowl XII played on January 15, 1978.The Pittsburgh Steelers beat the LA Rams 27-10 in Super Bowl XIV played on January 20, 1980.
2003: The Pittsburgh Steelers beat them 36 - 33.