Airylli has a variety of CafePress shops with quotes, the problems of eating an ice planet, and more. But the designs that stand out for me are the ones based on WWII posters, such as the one pictured ("Browncoats: They Fight For You") that includes Mal's "We have done the impossible" speech. Very nicely done designs that stand aside from the usual crowd.

Shirts, calendars, prints, buttons, etc.