I've been having a lot of fun with Pygame lately. My latest project is a clone of Atari's classic game, Breakout. Such a simple, yet addicting game. Here's a screen shot of the game I'm working on.
The code for it can be found here. And credit where credit is due, I borrowed some code from here and here.
The part I really had trouble with was how to change the angle of the ball's trajectory based on where the ball hits the paddle.