The strongest thing to consider in a comparison of the MacBook vs. PC laptop is the operating system. Chances are good that you have not used Mac OS X that much. However, you probably do have some experience using Windows. So, the first thing to consider is do you want to switch to a new operating system? Mac OS X Snow Leopard and Windows 7 have more differences than similarities. Thus, you will need to learn how to use the MacBook. Is the learning curve steep? Not at all. The majority of people who get Macs tend to pick up on how to use OS X rather quickly. Mac OS X is a good operating system that offers simplicity above all.
If you have Windows, and like it a lot, you may want to stick with Windows- why change a good thing? For some, learning new software is more of a hassle than an enjoyable experience. Windows 7 is another good operating system. There are more games that are available for Windows, more programs, and other utilities.
Macs can get viruses. However, they do not get viruses near as often as Windows PCs. This is simply because more people use Windows PCs. Viruses are distributed and targeted at the majority. The way OS X is designed does make it a bit safer to use. But Macs can get viruses.
Macs have the ability to run the Windows operating system easily and conveniently, as well as the native OS X. With a Mac, you could have Snow Leopard and Windows 7. From that perspective, you would not have to decide which to get, as you can have both.
PCs have the ability to run Windows. They are not supposed to run Mac OS X, and attempting to install OS X on a PC is not nearly as simple as most people would like it to be. However, it can be done.
For the most part, Macs are simple to use. PCs are a bit more complex, and offer more options.