The patriots. They went 16-0 in the regular season in 2008
ANSWER
If you're talking about a single season, the 1972 Miami Dolphins, who went 14-0 in the regular season and won the Super Bowl. (The '08 Patriots went 16-0 in the regular season but lost the Super Bowl.)
All-time, the Cowboys have the best winning percentage among existing teams. Dallas is 467-339-6, for a .579 percentage.
Otto Graham was 57-13-1 in the NFL and 109-17-4 overall, the best winning percentage of all time.
Chicago bears with 697 all time wins as of 10/20/08
The worst NFL record of all time is 0-16, achieved by the Detroit Lions in the 2008 season.
Among existing teams, the Cowboys have the best winning percentage. As of the beginning of the 2010 season, Dallas is 467-339-6 all-time, for a .579 winning percentage.
Brett Favre
Warren Moon, NFL quarterback between 1984-2000, fumbled 161 times during his career and holds the NFL record.
The worst all-time NFL record held by a team in the history of the league is the Tampa Bay Buccaneers' 0-14 season in 1976.
2009? Broncos Colts Giants Vikings Saints all have 4-0 record
Emmitt Smith 18,355 rushing yards
Brett Favre beat Dan Marino's all time passing touchdown record recently.
Rolland Lawrence is the Atlanta Falcons all-time interceptions leader with 39.
Dallas cowboys