Can you have booze in them? I've had excellent luck with these:
http://www.coconutandlime.com/2008/03/absinthe-makes-heart-grow-fonder.htmlHowever, a warning: cut back a bit on the absinthe if you got one of the more high-octane brands, and make absolute sure that your baking soda and baking powder are sifted very well. One of them exploded in my oven (literally. . . it forced the oven door open several inches). One direct hit to a heating element, and I had a fireball in the oven. (Closing the oven door cut off the oxygen, thereby extinguishing said fireball, but it was a rather alarming experience.)
I also have had good luck with strawberries and champagne cupcakes. I don't remember how I made them, though. I kind of winged it. But everyone liked them. If I do it again, I'll probably skip the buttercream in favor of an egg white-based icing.
Margarita cupcakes are also delightful. Rachel Ray has a good recipe (look for Tequila Lime Cupcakes), but I recommend upping the lime and tequila content and cutting back a bit on the salt.
I also once did a white chocolate mousse cake with raspberry mousse filling and fluffy white chocolate buttercream icing. That was a layer cake, but I bet it would work as cupcakes if you piped the filling in.