Allright, MAC viruses:
MDEF / Garfield
Sevendust / 666
Not to mention multiple carpetbombers, the Safari bug to name one in particular.
Enough viruses/trojans/worms? Apple even issued a warning that users should run antivirus software, contrary to what they claim in advertisements. They removed the page after a couple of months though.
On the topic of *Nix: every system has it's vulnerabilities. The unix, linux and BSD kernels are just as vulnerable to buffer or stack overflows as the windows kernel is. The windows and apple kernels are proprietary though, whereas the linux kernel is open source, which means everyone can point out errors in the code (which happens a lot), which result in a lot of updated packages each month. Windows patches are issued in a cycle, every 2nd tuesday of the month to be precise. Ever noticed the majority of viruses are unleashed just after that day?
That being said, I run both windows and linux, and I'd run OSX if it let me customize it a bit more, instead of force Steve Job's will upon me (I'm a power user, I want and need full control).
And remember: the mind is the best antivirus, and I've found windows users are generally more security concious/aware, where most mac users I've spoken to have this arrogant "oh my mac can't get viruses" mindset. Sad but true.
Disclaimer: I have not spoken to every single apple user out there. I'm sure there are security concious members too. I just found the majority to be ignorant or misinformed.
Credibility note: I'm an aspiring system administrator with a passion for computer security. I follow hacking sites, read whitepapers and try out 0-days for myself on my test machine.
Concluding: no, OSX is in no way less secure than windows, and I never claimed such thing. What I said was that macs are just as (in)secure as every other alternative out there, but because of it's larger marketshare, windows is the big target. Mac's are gaining marketshare, and that ignorant/arrogant no-need-for-antivirus will eventually backfire immensely to users who just don't know. Information is key, and all Apple is doing is misinforming their users and lying about windows.
that is all