Through Super Bowl XLII, that would be the Buffalo Bills and the Minnesota Vikings who have both played in four Super Bowls without a victory.
Six. Two with the New York Giants as an assistant and four with the New England Patriots as a head coach. He's been on the winning side in 5 of the six Super Bowls.
Pittsburgh Steelers have the most super bowls winning it 6 times
Through Super Bowl XLIV, both the Minnesota Vikings (SBs IV, VIII, IX, and XI) and the Buffalo Bills (SBs XXV, XXVI, XXVII, and XXVIII) have lost four Super Bowls without winning one.
The Buffalo Bills were in 4 Superbowls in a row without winning a single time.
Because that's the number of Super Bowls the Redskins have won. They have played in 5 Super Bowls, winning XVII, XXII, and XXVI and losing VII and XVIII.
The Steelers participated in eight Super Bowls. Winning six: IX, X, XIII, XIV, XL, XLIII and losing two: XXX, XLV.
The Green Bay packers played in 4 Super Bowls winning 3.
The Dallas Cowboys played in eight Super Bowls, winning five.