Err... Mac OS X runs on a freeBSD backend. Which is basically *Nix. So you could technically say MAC OS X is *Nix with Apple's GUI and applications. Sure there's a few minor differences but it's pretty much still *Nix.
Viruses, trojans, worms, or whatever is/can be written for all platforms.
A malicious program that could be the first Trojan in the wild to target Apple Computer's Mac OS X operating system has been discovered, security experts confirmed Thursday.
Not ever using Linux, I know enough to know that it isnt compatible with any games. I would rather get viruses and have fun then not get viruses and not have fun.
Good luck with that... I'd rather have my important data safe that would enable me to live in my home than have fun and have to move out in the end... either that or have to start all over again.