Having lived in Green Bay for several years with my family, I have been to a few Packer games. Since I moved to Green Bay as a teenager, I didn't have too much knowledge of other football teams prior and came to believe that Green Bay football games probably were similar to that in any other city.
However, now having lived in other cities with NFL teams (Houston and Minneapolis), I've realized how entirely wrong I was. Packer games are unlike anything else on Earth! Green Bay is a city of a little over 100,000 people, yet Lambeau Stadium hold almost 75,000 and is completely full for every game. Even in the bitter cold (think -10 or -20F with snow or howling winds), fans tailgate in the parking lot for hours before each game and sit in the open-air stadium for the entire game. At these temperatures, even your beer will freeze! Many small businesses shut down during games, and it is difficult for larger businesses to find workers during the game. If you didn't attend a game but are walking around the stadium in a half mile radius or so (much of the area around the stadium is residential), you will often get asked by partying fans at surrounding houses if you'd like a beer or brat when you're walking by. And in many other cities far from Wisconsin there are dedicated Packer bars that go just as wild. Why? Because it's the best team on Earth!
The pictures here are from a pre-season game that my husband and I attended, but you can see plenty more craziness at any other game!