The Raiders of the early 70s were pretty dang good.
In 72 they went 10-3-1 losing to Pittsburgh 13-7 on the immaculate reception. The Raiders really should have won that game. Steelers would eventually go on to lose to the Miami Dolphins in the conference championship 21-17 but had the Raiders been the team to move on, I don't know if Miami whould have gone on to win out and represent the AFC.
In 73 they beat Pittsburgh in the playoffs and lost to a great Miami Dolphins team that went on to win the Super Bowl in the AFC conference championship game. Close again but no cigar.
In 74 they went 12-2 losing only to the Bills 21-20 and Denver 20-17. They beat the Miami Dolphins team that had just completed an unbeaten season and two straight Super Bowl wins. They lost to Pittsburgh 24-13 in a very close game that some say, even today, was called in favor of Pittsburgh.
In 75 they went 11-3. They got thumped by KC 42-10, Lost to Cincy 14-10 and lost to Houston 27-26. They again lost to a great Pittsburgh team 16-10.
In 76 they finally managed to win the Super Bowl stomping the Vikes 32-14, going 13-1 in the regular season and destroying Pittsburgh 24-7 along the way.
This was truely a great team that had the miss fortune of being very good at a time when two of the all time best teams in the History of the NFL had it going, Pittsburgh's famed Steel Curtin and Miami's No name defense.
You look at Oakland at that time and they were as talented as anybody ever. Those teams bosted no less then 9 Hall of Famers in John Madden, Fred Biletnikoff, George Blanda, Willie Brown, Dave Casper, Ted Hendricks, Jim Otto, Art Shell and Gene Upshaw. Not to mention Ray Guy, Ken Stabler, Jack Tatum (who could all easily be in the HOF as well), Otis Sistrunk, Mark Van Eeghan, Pete Banaszak, Cliff Branch, John Matuszak, Marv Hubbard, Daryl Lamonica and Phil Villapiano.
That was a very, very talented team. I think that's probably my choice right there.