Something like this, like TheAppleFreak said, is user preference. I have used both in my lifetime. I like both. Windows does have weaknesses, like program compatibility (ROM tools not being compatible with Vista), and price. Let's compare.
Mac Vs. PC- Price
Both are relatively expensive. A Windows 7 Ultimate upgrade can cost up to $500. The price of a Tower for a Windows PC can cost anywhere between 400-1000 dollars. But, when you bbuy a Windows PC, you need to but the screen, and all the peripherals separately. Macs nowadays have everything in the screen- and this saves space. Macs, though cost between 1500 and 3000 dollars, though.
Mac Vs. PC- Availability of Programs
Windows has a wide variety of programs and games because it's widely used. Macs don't have nearly as much, but people that invest in WINE can use Windows programs seamlessly. Also, you can install Windows on a different Partition if you run a Mac, but Windows can't run Mac OS on a different partition, because of compatibility. Mac programs won't run on Windows either.
Mac Vs. PC- Security
Every day, viruses, malware, Trojans and worms are made to attack Windows users. The reason Windows OS is so susceptible to viruses is because if important files in the Computers are damaged or destroyed, it can make the system crash because the files that rely on the damaged/destroyed file won't operate correctly. Macs run differently. Each part of the system is separate, but work all together, so if one is destroyed, it can be replaced easily because you still have limited access to the OS. Windows usually will require a fresh reinstall. There are security programs for both though.
As stated above, it's all preference.