The 49ers.
Steelers
Pittsburgh steelers
The Buffalo Bills in Super Bowls XXV through XXVIII.
Yes ... not only are the Bills the only team to lose four consecutive Super Bowls they are the only team to ever play in four consecutive Super Bowls.
joe Montana 16
Buffalo Bills
Pittsburgh Steelers
Yes.
Vikings and Bills
For the NFL seasons 1980-1989, the 49ers won four Super Bowls (1981, 1984, 1988, 1989 seasons), the Redskins (1982 and 1987 seasons) and Raiders (1980 and 1983 seasons) won two Super Bowls, and the Giants (1986 season) and Bears (1985 season) won one Super Bowl.
No team has ever won super bowls with four different quarterbacks. In fact, only three teams have even won four super bowls: Pittsburgh, San Fransisco, and Dallas. No team has ever won super bowls with more than two quarterbacks. The Steelers won four with Terry Bradshaw and two with Ben Roethlisberger. 49ers won four with Joe Montana and one with Steve Young. The Cowboys won two with Roger Staubauch and three with Troy Aikman.
The Buffalo Bills played in four straight Super Bowls (XXV, XXVI, XXVII, XXVIII). They lost all four.