Here's what I would do:
- Pong
- Breakout
- Space Invaders (credit to GearSlayer360)
- Asteroids
- Tetris
- Pac-Man
- ????
- Make Money
Most importantly, those mechanics are known well-enough that you should be able to code those from scratch. You should not be looking for code for those games ... to mod.
Add Tic-Tac-Toe which is wonderful and under-rated. Make this in your first couple games.
As you make each of these games, look for ways to improve each one. Don't just get them functioning and move to the next, but really develop it. For example, improved physics, artificial intelligence, color changing events (indicates something changed), obstacles, and so forth.
Clinton