Historically: The Cleveland Browns have the highest historical winning percentage during the Superbowl era of any team never to actually win a Superbowl. In addition, the Cleveland Browns were generally regarded as one of the best teams outside of the old NFL in the pre-Superbowl era, playing in the now defunct AAFC.
In any one season: The best team to "not" win a Superbowl would probably be the New England Patriots of 2007, who were the only team to 16-0 and were upset in Superbowl XLII by a couple of freak plays (as well as an impressive effort from the Giants).
The Steelers. They have won 6 super bowl championships in the super bowl.
Although the Lions had a rich and successful history pre-Super Bowl era, the Lions have never played in a Super Bowl. The Detroit Lions are the only team in the NFC and the only non-expansion team to never have played in a Super Bowl.
The Broncos, Vikings, and Bills have all lost four Super Bowls. The Bills and the Vikings have never won the Super Bowl.
The 2007 Patriots went undefeated for the entire season until they lost the Super Bowl to the Giants. Unless you meant to ask what team has the best win-loss record in the history of the franchise, but has never won a Super Bowl, that would be your answer.
browns
Bills
No. The Hall of Fame quarterback never played on a Super Bowl team.
Houston Texans
The Detroit Lions.
There has never been a shutout in the Super Bowl. The closest was when the Dallas Cowboys held the Miami Dolphins to a field goal in Super Bowl VI in New Orleans.
As of 2010, Detroit, Cleveland, Houston and Jacksonville have never been to the Super Bowl.
The Minnesota Vikings...big chokers