Try to beat the computer at the board game Reversi (Othello). Some of the features: wide range of complexity levels, realistic graphics, undo/redo moves, save/load/construct positions, statistics, flexible logic and interface settings, color schemes.
Daisy Slider Puzzle is an attractive puzzle for all ages, computer variant of the known real game where you have to arrange rectangular pieces of a picture or numbers/letters in order by sliding them around. The program has a lot of handy features.