I voted for Supa Pong.
I almost went with SC Invaders, but I couldn't pass the first level. I think it would have been better if the space ships (whatever they are) would have moved all the way across the window instead of only a little bit past half way. That made it too hard to know where they were going to drop down so you couldn't aim for the end ships. It also made the ships come down too fast since they only had to move part way across the screen. Some inor improvements and SC Invaders would be a really good Space Invaders Clone.