Mm, in terms of “history” it’s the Chargers as they’ve gone the longest without ever winning it (and have only appeared at SB once, in 1994), followed by the much younger Texans who have never even been to the big dance (but have only existed since 2002). Meanwhile the Chiefs haven’t been since 1969 but did at least win it then.
On the flip side, this means the Cowboys and Patriots are to be avoided at all costs, and should the Superbowl come down to them this or any year the rest of the fans will most likely go find something better to do with their Sunday.
In terms of this current season however, it’s hard to describe anyone as plucky underdogs as the traditionally less successful teams, such as the Chiefs or the Rams or, to an extent, the Saints, have done really well this year hence their collective byes into the next round. I guess Colts are technically the biggest underdogs as they had to win their last match of the season to get in as while the same is true of the Eagles they are the defending champs which takes the shine off a little.
Basically, this is my round about way of me saying fuck the haters, support the Ravens, this year’s (and every year’s) good guy underdogs.