Do you have a favourite quote that you love?
Everyone does don't they?
Here are a couple from Firefly, but you really are limited only by your own imagination (and the fact that you can fit a maximum of around 18 characters to a line).
Declare your love of the geeky, stand up and be proud of your fan heritage by proclasiming it for all to see on your wrist. Please specify the text you would like on the cuff and ideally what configuration in the form of 

Line 1: I Swear

Line 2 By my pretty floral bonnet

Line 3: I will end you

triple band geek strap