Well with Ubuntu unlike Windows you're always working with the system files so if you mess up one thing then you're screwed and have to reinstall. I personally don't recommend it. You also need to type the commands to even extract files from things like .zip correct me if I'm wrong.
Theres OS which has the spinning box thingymabob installed ready... (I forgot the name again, I need to work on my memory )
and all your games cant work on it, you dont have directX, and I never myshelf tried how GameGuard works with my Ubuntu... I have feeling that theres no way it will work.
Why Linuxes and Mac:s dont get viruses, most people use Windows so for those who make them (them=viruses) its better to make virus for windows than Mac.