Does anyone program for programming's sake? Can you lead a horse to water AND make it drink?
Show a kid what the possibilities are first, which means learn what you want to teach them. Also, instant gratification is key - no kid wants to be there writing what seems like arbitrary lines of code so that they can see the Fibonacci sequence rendered up to n terms. My top 3 suggestions as a computer science teacher:
1. Scratch: free, online, massive community, tweak stuff before you make your own, instant gratification. There's some complex stuff out there so try to restrict examples to simple ones, stuff that they can try to emulate themselves. Kids will typically have very high expectations of what they can achieve without appreciating the complexities involved. Code is built using drag and drop. It's not immediately intuitive but you can get results very quickly once you pick it up.
2. Minecraft Pi: get a Raspberry Pi. The Raspbian distribution comes with a special version of Minecraft that has a Python API attached to it, and there are some very simple examples on the RPi website that can get you rendering all sorts of cool stuff in the Minecraft environment within minutes. Pixel art made from blocks, a digital clock floating in the sky, hunt the diamond, Midas touch, the list goes on. You can tweak the existing code after copying it out (like we used to do from coding magazines) before trying out your own programs. Also exposes him to an operating system other than Windows.
3. Spirograph: technically I mean 'turtle'. It's a great way for kids to learn about randomness, iteration, geometry and efficient coding tecniques. Scratch, Small Basic and Python all have a turtle module built in so you can draw shapes on screen very quickly and easily.