The Arabs were unusually good at insults, such as:" may the fleas of a thousnad camels nest in your armpits".
Acually insults are silly unless done in fun.
Here's a fun site:
http://www.mainstrike.com/mstservices/handy/insult.html
Another one just came to mind, from country music:
"may the blue bird of happyness fly up your nose" (Little Jimmy Dickens)