Genki Hats has moved to a keen new site, and added a number of new hats! I like the Lonely Bunny Hat myself:

Are you a lonely bunny? Do you wander the city not belonging? Who are you really? This hat will help you discover your true self. (self discovery not guaranteed)

Now I just need to see if they'll do an Alien 9 hat for me. Though that would probably be hard with the wings.