I realized that touch screen monitors such as my Dell SX2210T is pretty useful when using applications that requires a lot of point and click/tap actions. A typical example of such application is computer games.
I like to play chess games and card games, either with human or with computer AI.
Windows 7 Home Premium (and above) comes with a pretty nice game called Chess Titans. Its AI isn't that strong and you can easily defeat the computer.
Beside Western Chess, I also like to play Chinese chess. There is an open source Chinese chess game for Windows called Qianhong (浅红) by Jeremy Craner, which you can download here.
The GUI of Qianhong isn't great at all, but I care more about its features. Qianhong supports severate modes of playing including human-human, human-computer, and computer-computer. It also supports playing across the network.
Its 3-level AI is pretty weak not challenging at all. However, Qianhong supports AI plugins which you can download from their website, including 10-level Ki11egg AI by Tzer-jen Wei, 5-level VSCCPW by Pham Hong Nguyen, 5-level ElephantEye by Morning Yellow, etc.
By using the computer-computer mode, you can let the same or different AI of same or different level to compete between themselves, and you be the observer to learn their tactics.
Another free Chinese chess game I like is XieXie Master (谢谢大师) by Pascal Tang.
XieXie Master has a better looking GUI than Qianhong, but it doesn't have computer-computer mode. However, it has features that Qianhong doesn't have, including "handicap", etc.