The mac hate here is intense, especially for people here who have obviously never used one. I've also got my nice shiny built by myself gaming rig running Windows XP sitting next to my nice shiny Macbook Pro. OSX is the easiest to use operating system on the market today. Vista over-complicates things, hides menus, and is just a sheer patch job when it comes to UI. XP is still the best commercially released build of Windows, but its old. Sure Windows 7 should fix that, but even then Windows 7 vs Snow Leopard isn't even a contest. This is based on tests I've done with RC builds of Windows 7 vs Snow Leopard.
There are viruses for the Mac, this is true, but they are so insignificant compared to the threats Windows has against it that its not worth even mentioning. You get a Mac virus, typically, by installing pirated software. You get a Windows virus by opening an email, leaving it idle on the net, going to a malicious website, installing illegal software, etc. The list goes on.
At this point the only advantages I give to Windows is gaming and cheap upgradability.