Super Bowl XLVII: 108.41 million viewers.
Which seems like a lot of viewers. Which (darn it) is a lot of viewers. But ... not the most viewers. CBS said this was the third most-watched program in TV history, behind Super Bowl XLVI, with 111.3 million, and Super Bowl XLV, with 111.0 million.
But here's the reason for the "but": CBS did not wrap in viewership for the blackout -- about 40 minutes or so -- and there was a good reason for that. No ads aired during this portion of the game, so there was no reason to measure it. (CBS could not place ads during this part because there are long and hard negotiations about exactly where ads are supposed to air during the Super Bowl, and none of those discussions have anything to do with a "blackout contingency.") Would the rating have been even higher, when a few million more rubberneckers flew to the network to see what all the fuss was about? Possibly, but we may never know; CBS did say that metered market ratings did indicate a record.
CBS added that "Last night’s Super Bowl HH rating/share peaked at a 50.7/73 with an average of 113.92 million viewers from 10:30-10:47 p.m., ET."