3D acceleration in Linux is still a feature to improve.
What's your graphic card?
Have you tryied to download an official driver of the graphic card for Linux?
What are the frecuency and resolution your monitor can handle?
What are the games you want to play?
Are you willing to use a dual boot with Windows only for the games?
Are you willing to spend money for an OS that fully supports 3D acceleration and is still reliable (Mac OS X)?
You my also try programs like VMware (emulates the whole Windows OS from Linux), WINE or CrossOver Office (runs some Windows applications directly from Linux), or CEDEGA (specialized in playing games in Linux, it may have a better 3D acceleration support).
Hope this helps