History will be hard to repeat...

As we were watching the G-men pull out the win in OT i started to think... which will be harder to repeat? 1 of 2 things will happen, Either the Pats will finish off the first 19-0 season, or 2 Brothers will have won back to back superbowls. Just wondering which you guys thought would be the hardest one to repeat... My personal vote is for Back 2 Back superbowl wins by brothers, It might be another 35 years or so, but my guess is someday another team will run the table and go undefeated again. What do you guys think?