I wear a straw hat to the majority of games, especially when its hot outside. I bought mine from Cavander on 610 near Reliant.
I didn't buy the nicest hat Cavander's had because I knew it would get ratted out tailgating. Good thing is, it gets alot of character during the season. As far as decorations, I don't do much along those lines but I collect the Verizon Game pins.
Here's a good reason to wear a cowboy had vs. a baseball cap: Buy the hat with the most gallons as posible. When its really, really hot out side and your sweating up a storm anyway, fill the top of your hat with ice and put it back on your head. Works wonders.