When i was at pizza hut last i saw a modified Pong game that I wanted to try and code. It was setup like a hockey rink. You didn''t score by getting the ball (puck) past your opponents paddle, but by getting it into a net. Sort of adds another level to pong. and hockey pong adds the ability to include good sounds and animation. Lights and air horns and crowd roars...
I would say, do hockey pong and learn about the very basics of game coding, and the whole of game design, which includes excellent graphics and sound, high scores, opening screens & demo modes which the game cycles through untill someone starts playing it.... and so on.
You should also check Geoff Howlands (Chief Executive Officer of this gamedev.net website) page at: http://www.lupinegames.com/
At the front page you find a table with dates, dated at 06-28-99 there is an article called "How do I make games?". In the article he lays out a "roadmap" for aspiring game programmers to follow, starting with Tetris and then advancing to more complicated things.