(Ed's Note: A version of this piece originally ran in December 2006. It's been updated to reflect recent historic accomplishments in the NFL.)
By Jonathan Comey
Cold, Hard Football Facts history buff
History is littered with the almost-greats: teams that dominated the NFL throughout the regular season, but just couldn't close it out in the playoffs.
Below is a nod to the great teams of the Super Bowl Era that didn't win it all, the teams and the fans that lead lives of regret, wondering what might have been.
Perhaps the greatest teams to fall short of a title came long before the NFL took its place atop the American sporting landscape and long before the creation of the Super Bowl in the 1960s. The two most notable "almost-greats" belonged to the same franchise, the Chicago Bears.
The 1934 Bears were the defending champs and a juggernaut. Coached by George Halas and led by running back Bronko Nagurski (a member of the Cold, Hard Football Facts All-Time 11), the Bears went 13-0 and won each of their first nine games by at least two touchdowns. They scored 286 points in the regular season and allowed just 86.
But the Bears peaked too early. They struggled to win three of their last four and then lost, 30-13, to the 8-5 Giants in the title game.
Sound familiar, New England fans?
The 1942 Bears might have been even better. They were also the defending champs and stand as the single most dominant team in NFL history. They went 11-0, scored 376 points and allowed just 84. The average scoring margin of 26.6 PPG (34.2-7.6) is unmatched in league history. Then they fell apart in the championship game, losing to the 10-1 Redskins (in Washington for some reason), 14-6.
Any pain from the historic loss was tempered by World War II. George Halas himself attended the game as a spectator: he was already in the Army. Several players were sworn into the military hours after the game.
If any of those old Bears are still alive, the loss probably still wakes them up angry every now and then: "We shoulda been perfect!"
Undefeated teams are nearly an extinct species in the NFL – as we all know, only one has ever been sighted. But there are plenty of great teams in the last 40 years that have followed the lead of those star-crossed Bears: teams that looked unbeatable, but fell short of their destiny.
So today, we salute what might have been, and present the Top 10 non-champions of the Super Bowl Era. The 1990 Bills, No. 10 in our original list, are gone. They've been booted off the list by, well, you probably know the answer.
Here, then, are the 10 greatest teams of the Super Bowl Era who failed to win it all.
Coach: Chuck Knox 
Record: 12-2 
Offense: 27.7 PPG (1st)  
Defense: 12.7 PPG (4th)
Pro Bowlers: 8 
Five best players: DL Merlin Olsen (pictured here), RB Lawrence McCutcheon (5.2 YPC), WR Harold Jackson (13 TDs), OL Tom Mack, DL Jack Youngblood
Sob story: Led by first-year coach Chuck Knox, the Rams came within a couple of field goals of replicating the perfect season of the 1972 Dolphins; their two losses (on the road at Minnesota and Atlanta) came by a total of three points. They had eight Pro Bowlers, the top scoring offense in the NFL and an Olsen-led defense that would become the best in the league in 1974. The 1973 Rams were primed for glory ... and then they lost their playoff opener, 27-16, to Dallas. Oops.
Coach: Joe Gibbs 
Record: 14-2
Offense: 33.8 PPG (1st)
Defense: 20.7 PPG (11th)
Pro Bowlers: 6 
Five best players: QB Joe Theismann, RB John Riggins (24 TDs), OL Russ Grimm, OL Joe Jacoby, DL Dexter Manley

Sob story: The Redskins were coming off a Super Bowl win in the strike-shortened 1982 season, and looked to add a more legitimate crown under their hot, young coach, Joe Gibbs. Their defense was just good (11th in the league), but the offense scored a then-NFL record 541 points. This was a team littered with stars on offense: the Hogs, the Diesel, the Fun Bunch, and MVP quarterback Theismann. They entered the Super Bowl with an 11-game win streak, including a 51-7 demolition of the Rams in the divisional round, and were prohibitive favorites against the 12-4 Raiders in the Super Bowl ... but they just lost, baby – 38-9, no less. 

Coach: John Rauch 
Record: 13-1 
Offense: 33.4 PPG (1st in AFL)
Defense: 16.6 PPG (2nd in AFL) Pro Bowlers: 12 (pre-merger) 
Five best players: WR Fred Biletnikoff (21.9 YPC), OL Jim Otto (pictured here blocking for ...), QB Daryle Lamonica (30 TDs), DL Ben Davidson, DB Willie Brown

Sob story: This might have been the AFL's greatest team. No other club in the 10-year history of the league matched its 13-1 record, and it was teeming with Raiders legends in various stages of their careers. They scored 468 points in 14 games – still among the greatest offenses of the Super Bowl Era – and had a four-game edge on their closest competitors, the Oilers, who had the decency to lose 40-7 to Oakland in the league title game. The Raiders were given a chance in Super Bowl II against a battered Packers team that finished 9-4-1 while clinging to the last vestiges of its dynasty. But they lost 33-14 in a game that seemed to prove the almighty dominance of the NFL.

Coach: George Seifert
Record: 14-2 
Offense: 26.9 PPG (1st)
Defense: 14.7 PPG (3rd)
Pro Bowlers: 7 
Five best players: WR Jerry Rice (1,201 yards, 10 TDs), QB Steve Young (107.0 rating), OL Guy McIntyre, RB Ricky Watters (11 TDs, 1,418 yards from scrimmage), DL Tim Harris (17 sacks)

Sob story: The 49ers didn't lose a Super Bowl in five tries, but suffered plenty of postseason disappointment. Their 14-2 team in 1990 fell in the NFC title game to the Giants. Joe Montana was injured in that game, effectively ending his career in San Francisco while opening the door for Steve Young. This 1992 team, another 14-2 juggernaut, exceeded the disappointment. Young was brilliant in his first full season running the offense and earned MVP honors. The 49ers also beat some top competition, with a 6-1 record against playoff teams heading into the conference title game against the upstart Cowboys. But they lost, at home, to eventual champ Dallas, 30-20. In Bay-ville, they say that the small monkey on Young's back grew three sizes that day. He would famously remove it two years later with 6 TD passes in a Super Bowl win over San Diego.

Coach: Mike Martz 
Record: 14-2
Offense: 31.4 PPG (1st)
Defense: 17.1 PPG (7th)
Pro Bowlers: 5
Five best players: OL Orlando Pace, RB Marshall Faulk (2,147 yards from scrimmage, 21 TDs), Kurt Warner (MVP), WR Torry Holt, DB Aeneas Williams

Sob story: The Rams and their "Greatest Show on Turf" offense won the Super Bowl in 1999, bumbled through a 10-6 campaign in 2000 as their defense decided to take the season off, and then returned to form under second-year coach Martz in 2001. Marshall Faulk scored 21 TDs and averaged 6.3 yards every time he touched the ball. The Rams outgained opponents by an average of 137 YPG, they became the first team in NFL history to score 500 or more points in three straight seasons, and their average game was a 14-point blowout. They were favored by that many points in their Super Bowl coronation lap against overmatched New England, an 11-5 team that didn't even know who would play quarterback until three days before the game. But the Patriots physically beat up Faulk, the St. Louis receivers and two-time MVP quarterback Kurt Warner, and held on for a 20-17 win.

Coach: Bud Grant 
Record: 12-2 
Offense: 27.1 PPG (1st in NFL)
Defense: 9.5 PPG (1st in NFL)
Pro Bowlers: 7 (pre-merger) 
Five best players: DL Alan Page, DL Carl Eller, DB Paul Krause, WR Gene Washington, OL Ron Yary

Sob story: The first of Minnesota's four Super Bowl losers, this Vikings team had it all: the best defense in the league, the best offense in the league, nine Pro Bowlers, five future Hall of Famers and a great leader in fiery quarterback Joe Kapp (pictured above). Their defense was so good that it remains one of the stingiest in modern NFL history. They lost their regular-season opener and finale, but won 12 straight in between. When they reached the Super Bowl, they were primed to put an end to the upstart AFL, which had broken through with the Jets the year prior. Instead, the AFC officially arrived as the Chiefs humiliated Minnesota with a 23-7 beating. As far as upsets go, it was just slightly sub-Namath in proportions.

Coach: Don Shula 
Record: 14-2 
Offense: 32.1 PPG (1st)
Defense: 18.6 PPG (7th)
Pro Bowlers: 7 
Five best players: QB Dan Marino (48 TDs), WR Mark Clayton (18 TDs), WR Mark Duper (1,306 yards), OL Dwight Stephenson, LB A.J. Duhe

Sob story: Dan Marino's only trip to the Super Bowl came with what was clearly his best team. The Dolphins had a stifling defense and an effective ground game that accounted for 18 touchdowns, while Marino rewrote the NFL record books with 48 TD passes and 5,084 passing yards (still the NFL standard). Mark Duper and Mark Clayton were in top form – they combined for 144 receptions, 2,698 yards and 26 TDs, and each averaged more than 18 yards per reception. Mesmerizing numbers. Marino was the story of the year, and the Fish swam through the AFC playoffs without as much as a wave, outscoring their two opponents, Seattle and Pittsburgh, exactly 2-to-1 (76-38). One problem: Their Super Bowl opponent was better. The 15-1 49ers were also explosive on offense, but they had the league's best D to back it up. It was supposed to be the greatest Super Bowl of all time, and it was ... for San Francisco, which won 38-16.

Coach: Dennis Green 
Record: 15-1 
Offense: 34.7 PPG (1st)
Defense: 18.5 PPG (6th)
Pro Bowlers: 9 
Five best players: WR Randy Moss (17 TDs), WR Cris Carter (78 catches), DL John Randle, QB Randall Cunningham (34 TDs, 10 INTs), OL Randall McDaniel

Sob story: The Vikings scored 556 points, thanks in large part to the unstoppable receiving duo of veteran Cris Carter and rookie sensation Randy Moss. No team in NFL history had ever scored more points in a single season (to that point). Their only loss was a three-point job in Tampa, and they reached the NFC championship with ease. In the late stages of that game with Atlanta, Minnesota sent Gary Anderson out to kick a 39-yarder and take a 10-point lead – the same Anderson who was a perfect 35-for-35 on field goals in the regular season. What could go wrong? Of course, Anderson missed, and Atlanta went on to win in overtime. The Vikings' quarterbacks and coaches have changed over the years, but their bridesmaid existence has continued – even their best teams have never been quite good enough.

Coach: Don Shula 
Record: 13-1 
Offense: 28.7 PPG (2nd in NFL)
Defense: 10.3 PPG (1st in NFL)
Pro Bowlers: 8 (pre-merger) 
Five best players: TE John Mackey (644 yards), QB Earl Morrall (26 TDs), LB Mike Curtis, DB Bobby Boyd, DL Bubba Smith

Sob story: The Colts were already a frustrated bunch going into the 1968 season. In 1967, they were 11-0-2 heading into the final game of the season, but they missed the playoffs by losing to the rival Rams in that finale. The NFL had gone to a divisional format that year for the first time in its history, and when both teams finished 11-1-2, it was the Rams who earned the Coastal Division's only spot. The mighty one-loss Colts sat at home while the NFL sent three nine-win teams to its first-ever playoff. It got worse in 1968. The Colts had the NFL's No. 2 offense and No. 1 defense in 1968, and with their 34-0 shutout of the Browns in the NFL title game, the world championship was basically theirs. They just had to handle the AFL pretenders from New York ... which, of course, they didn't. Joe Namath parlayed Super Bowl III into a Hall of Fame ticket (and years of charming tipsiness). The Colts had to settle for their role as the greatest non-champion of the era.

Coach: Bill Belichick 
Record: 16-0
Offense: 36.8 PPG (1st)
Defense: 17.1 PPG (4th)
Pro Bowlers: 8
Five best players: QB Tom Brady (4,806 yards, 50 TD), WR Randy Moss (23 TDs), WR Wes Welker (112 catches), LB Mike Vrabel, NT Vince Wilfork
Sob story: The 2007 Patriots were the big bad Evil Empire, mired in scandal, hated by everyone outside New England – and yet literally unstoppable for most of the 2007 season. They set Super Bowl Era records, and even all-time records, in every imaginable category: points (589), scoring differential (+19.7 PPG), TDs (75), victories, blowout victories (10 by three TDs or greater), you name it. Future Hall of Fame quarterback and three-time champion Tom Brady played at the peak of his powers with one of the great seasons in history, tossing a record 50 TD passes, with a record 23 caught by Randy Moss alone. And, of course, the Patriots became the first team to win every regular-season contest in the 16-game era (since 1978). And, including the end of the 2006 season, they even set a new NFL record for consecutive victories, 19, besting the mark of 18 held by the 2003-04 Patriots (NFL records include only regular-season numbers).
And then they forgot to show up for the Super Bowl, scoring just 14 points, their lowest output of the year, against one of the worst teams ever to reach the championship game: the 10-6 Giants who had outscored their regular-season opponents by just 22 points – not much different than the scoring margin in an average single game for New England in 2007.  It's hard to envision a scenario in any sport in which a team could play so far above its competition for an entire season ... and then kind of forget to win the championship. Football fans in 44 states and several Third-World nations are still doing joyous, tribal war dances around the glow from the burning embers of the empire's collapse.