Ok, so this isn't the most useful example of Flex, but I have a soft spot for the old Lemonade Stand Apple IIe game of my youth. I rebuilt it with Flex:
http://ray.camdenfamily.com/demos/ls/main.html
It still has a few quirks, but have fun. I've also included the source code as an attachment to this zip. Please note that I'm very much a Flex newbie, so don't consider my code as anything even near "Best Practice".