Tumblebug

Tumblebug is a good game for younger kids.  It's simple and fun.  It coordinates color recognition.

You try to match three of the same color in a row and you shoot a colored ball to make the three in a row disappear.  When all the balls disappear, you advance to the next level. 

I recommend before you buy this game, you try their free download at Big Fish Games.

Age of Empires III

Age of Empires III is a fun, historical action game filled with excitement of commanding military units in a strategic style.  It is easy to learn and fun to play.  This is my favorite game.  

Hero RPG @ http://www.freeworldgroup.com/games6/gameindex/hero-rpg.htm

Hero RPG is a fun game if you like action and fantasy. It is simple to play and easy to learn. It is an adventure where you collect items, you fight characters, and, in general, have fun.

There are only three types of characters you can choose from. Besides that, I think it's a pretty good game and you should try it.