Atlanta Falcons - At first, I was a pretty big fan of this hat. I've cooled on it a little, only because it is a bit too shiny to wear everyday - but this hat would go well with a black Falcons jersey - unless it is Michael Vick.
Seattle Seahawks - This hat looks like a kindergartner or one of John McCain's staffers threw up all over it. I guess this hat is supposed to go with Seattle's new alternate jersey, but it mainly gives me a headache. Wow.
San Diego Chargers - I really like the old school powder blue Chargers jersey and I'm pumped they've brought the look back. This hat is pretty cool, but if you're going with a throwback design, you might as well go with a throwback looking "relaxed fit" hat instead of a shiny techie looking hat like this. As you've seen with Seattle, however, you could make a far worse choice.
Minnesota Vikings - Again, I like to wear hats that you can wear everyday. That's why the New York Yankees or Boston Red Sox hats are so popular - subtle navy with a white or red accent. Purple and yellow with stripes, on the other hand? Not so subtle. I think most of these hats could be worn with a jersey - this one would go well with the Vikings white away jersey - but wouldn't look so great for everyday use.
Houston Texans - This hat is pretty similar to the Atlanta Falcons hat. Pretty good color scheme, not too overwhelming. 
Carolina Panthers - The Carolina Panthers logo is just so painfully 1990s. The neon teal color scheme is not unlike the Jacksonville Jaguars - which entered the league at the same time. And lest we forget, the 1990s also witnessed the expansion of the Florida Panthers hockey team - so that decade couldn't even pick an original team name. And color scheme? Remember the San Jose Sharks? If you're a Panthers hat, go with a black jersey and hat.