I have created my cv site and sent out my demos for a while now, but most of my demos are either from my course or games related since my course was a games programming course, I was wondering what kind of demos are good to show off my skills in programming in general.

These are what i already have

• Pennies:just a simple game first coursework i did.
• Compiler:coursework for compiler writing module
• Pongout: basic a pong game in 68k using colour detection
• Snake: snake in 68k same thing as the pong
• Game Cube Maze: gamecube work
• BeatmyBot: basic Ai
• Basic plat-former game: 2d game with different types of collision
• Turing Lambda Simulation: my dissertation Turing machine simulated in Miranda. alpha and Beta reduction,and SKI calculus simulated in the Turing machine.

What I am asking here is what kind of demos are good to add or have, i have been looking and have hit a tough spot I cant think of anything to make more than games. so for a general graduate software engineer what types would be good examples?

EDIT: since responding to the comments bellow well for what languages well my main one would be C++, followed by Java, Erlang and abit of Haskell