Kryptek camo is pretty popular among the more fashion conscious airsofters, and since I assume they have heads, hats in their swanky camo patterns could be a good thing. I've been sent two from Supremeco that are actually a bit better than I expect from your regular baseball cap, first one is the "makhai":
Which comes in kryptek's Mandrake woodland pattern and has a velcro square on top instead of a little button like on most caps. This means that you can stick a tiny patch or strobe etc to the top of your head for aerial identification. Or if you're one of those boring people that live in