Win7 being more secure over osx? Doubt it. I help the IT guy with minor stuff at work; 90% of the folks have Windows and the other 10% use Mac. For the past year that I've been there not one of the Macs have had any security issues. I've had to clean, re-image a ton of Windows based laptops and desktops because of stupid stuff that goes on in Windows. Just today I had to clean an XP laptop from malware. I know there are viruses out there for the Mac but people that want to do the most damage focus on the majority; Windows.
The games, software, etc Windows wins in that category cuz again, the folks that make them want the most money and Windows fits that market. I've been able to play CoD4 since patch 1.5 on my Mac so I'm quite content. Like I've said it before, osx just needed CoD4 and I'd be set.
Matter of fact I'm running Windows 7 on my Mac via Parallel. I can easily switch to XP if I want to get my full gaming on.
Don't knock osx just cuz of the price because lets face it, that's literally the only bad thing about it. Besides you don't have to pay to use osx. But sshhh, don't tell Apple