1. Washington Redskins - the most loyal and patient fans of any NFL franchise (327 consecutive sellouts) still sport the traditional (and now un-PC) feathers & facepaint, dresses, and pigmasks... even at opposing stadiums
2. Pittsburgh Steelers - They've got the 2nd longest streak of sellouts (308), plus generations of champions with just 3 head coaches in 40 years = six-year waiting list for season tickets
3. Dallas Cowboys - America's Team has (just) 154 consecutive sellouts but their fans are located worldwide. You'd have a hard time finding one that hated you, even in their new billion dollar home.
4. Indianapolis Colts - Within the Dome, the fans were so loud they were accused of piping in sound to disrupt the opponents. While the new Stadium can't offer that anymore, Indy still provides jealousy from others, at least until they aren't winning 12+ games every year
5. Green Bay Packers - They oughta be ranked higher, however they handled that Brett Favre situation poorly, and then took frustration out on Aaron Rodgers.
6. Kansas City Chiefs - The Green Bay of the AFC, their fans are the loudest and they play outdoors
7. Cleveland Browns - Losing the team in '95 hurt the Browns Backers substantially, but they still can be seen at some remote bar in just about every American city on a Sunday afternoon
8. New England Patriots - ranked this low due to lack of loyalty, creativity and national presence
9. Philadelphia Eagles - Nobody gets on their own players as much as these guys do, often to a fault. Maybe the biggest base among non-transplant cities (sorry Miami, Denver, San Diego, Phoenix, etc)
10. Chicago Bears - These faux-blue-collarians are fair weather and delusional
Honorable mention: Oakland Raiders - more of a Sunday morning Halloween party than anything, but they still HATE like none other