There's allot of favorites but that 1974 championship game was the one that sticks out as my favorite because it was so symbolic as Chico pointed out. The Steelers had finally arrived and everyone knew it. They were down by 7 going into the fourth quarter and ran off 21 points to Oakland's 3. The defense was so dominant in the second half and as soon as they grabbed the lead, you could see they weren't going to be denied.
There were 17 players (9 from Pittsburgh, 8 from Oakland) combined from those two teams who would go to canton and both head coaches. There is at least one or two additional who should be in the hall of fame and so many others that were really good football players. Think about that, almost half the players on the field were gold jacket worthy.
It was a championship game that's probably unmatched as far as two great, iconic teams facing off.