What should the fast to slow song ratio be at my wedding reception?

I don't know about you but I don't enjoy listening to slow songs at a party. They bore me. As long as you play the one that you will dance to for the traditional dances + a few extras (and I use the word "few" loosely), the rest of the songs should be fun and happy songs. After all, this is a happy moment for the two of you, right? :)