Gaming Question

I don't know of many boxed CD games for Linux, they are mainly distributed online with serial numbers. Cedega from www.transgaming.com can play many games made for Windows. The full version costs £3 a month (or $5) for a minimum of 3 months. With that subscription you can download as many game installers as you like from their site.
There is a CVS version of Cedega available (CVS is a way of accessing source code), it is on transgaming.com as well. It is free, but it is not as full-featured (it has 3D support, but no support for cracking the games' copy protection, since transgaming need a license to do this which costs them, and therefore you, money)
For many really basic games WINE will work, it is available in Ubuntu's Universe package repository (and the WINE developers on www.winehq.org also offer a slightly more up-to-date version in their own Ubuntu repository). Note that WINE takes slightly more setting up than simply clicking on the package for 64bit PC users, since there are hardly any (none?) 64bit Windows applications for it to run. (Cedega is based on WINE by the way)

If it doesn't even run in Cedega then you can get VMWare as the most expensive option, running Windows inside VMWare on Ubuntu. This is the most expensive as you need a license to run Windows (VMWare costs nothing, but it is not Free Software/Open Source. VMWare-Player is in Ubuntu's Commercial package repository, but you may need a different version from www.vmware.com as the player is very limited)

It's not exactly what you asked I know, but if you want to play a decent looking native Linux game you should download armagedatron
'sudo apt-get install armagedatron', it's definitly worth it in my opinion.

There's also an article at 'http://techgage.com/article/top_10_free_linux_games' that might take your fancy.

Sorry, typo with the armagetron. The command to install would be:
'sudo apt-get install armagetron' instead.

My bad.