If Simms hadn't gotten hurt in 90, I would probably go with the 90 team, they were dominant and prior to Simms getting hurt I believe they were 10-0. That being said I would go with the 86 team. The defense was about as good as any in the history of the game. You actually looked forward to that defense being on the field because they were as likely to make a big play as the offense was. Teams feared that defense, who could blame them? I would not want to be a QB looking at those guys knowing that eventually I had to take the snap.
On the offensive side, they just dictated to the defense, everyone knew they were going to run the ball, but no one could do anything about it. They essentially went out there and did what they wanted to do and few did it better... ever. They weren't a great passing team, not because of talent but because they didn't need to pass the ball. Simms was a very good QB and proved that in the SB.