THE TRUE NATIONAL SPORT: Unqualified Offerings has a great defense of NFL football. He also points out the goofy love of people like George Will for baseball:

It's odd that baseball gets the intellectual cachet, since football is a far more intellectually-challenging game. Offensive and defensive playbooks are famously complicated, and their intricacy and depth goes beyond the sheer volume of material to be memorized. Behind an offensive system is a set of principles given concrete expression in a precise vocabulary, combined and recombined into individual plays and entire game plans.

He also makes the point that a source of football's greatness is its rest period (which soccer and hockey and other "fast moving game" partisans love to point out, but derisively.) It adds suspense, Jim argues. And he makes this unique point:

One also hears scoffs at the idea that many football players should even be considered athletes. Aren't a lot of them fat, not to say steroid-soaked, lummoxes? Leaving aside the steroid question, a lot of football players are big, fat and tall. They're called linemen. As it happens, offensive linemen are likely to be the smartest players on the field. Other football players are much thinner and much faster. There is a mild advantage to being shortish if you are a running back and a substantial advantage to being tall if you are a receiver or a defender. Some quarterbacks are very slow and some are very fast. So let me turn the complaint around and throw in a totem word for good measure: Football makes productive use of a greater diversity of somatic types than any other sport. You can be a 340# lineman, a 240# linebacker or a 180# cornerback. What has baseball to offer the 300-pounder? Should they all just sit around feeling sorry for themselves?

NFL football is America's sport, in popularity and in society-wide importance. What other sport's championship is a national holiday?