Log Sailing Row your boat across the Niagara Falls - simple, easy and freeware
TicTacTocToe Play 3D naughts and crosses (also called Qubic and tic-tac-toc-toe) on your PC. Choose one of 4 computer opponents and you can tinker with the AI. There are options to take back moves, set the computer to play itself, rotate the view.
Chomp This nifty little freeware programme plays the game chomp against you. You have to avoid finishing a rectangular chocolate bar as you take turns to eat rectangular bites. There is nothing to install, just run the exe.