Mac vs. PC....
The end result is that both platforms have their advantages and their disadvantages.
With Macs, most of the advantages of them can be attributed to those of having a single hardware and software vendor. From a perspective of any computer system, when the hardware and software are controlled by the same vendor, you have the definite advantage of increased compatibility that comes from the resulting level of quality control. The downside of that is decreased availability of applications and a less diverse array of hardware options, and higher price.
PCs are just the opposite... there is a much wider array of software and hardware options, but the increased number of options lead to the stability and security challenges that are out there. It's Windows own incredibly broad hardware and software support base that leads to it's disadvantages...
The other big advantage often touted by Mac users is the lack of viruses and spyware, combined with the increased security of the OS. However, it's Mac's own limited user base and market share that lead to this. If the roles were reversed, with Mac controlling 90% of the PC market, you'd probably find a whole lot more problems in this category. As a virus or spyware writer, you want to affect the larger market share.
In the end, as tough as it is for me to not bash Macs, I dislike arguments that try to make a claim that one platform is better than the other. In the end, they are just different, and in either case, you are making choices based on the pros and cons of each platform. The same thing goes for Linux... not better or worse... just different. For me, the pros of Windows on PC hardware far outweighs the pitfalls.