I used both computers before. I have an windows laptop but I rather an mac over an windows. I don't have one because they are very expensive. If you have the money for the mac then go with that. You will love it!
I prefer Windows just because it's what I'm used to. I have been using Windows ever since I was a teenager so I've grown up with it.
I was a windows user many moons ago. I jumped ship when the first imac came out and I've never looked back. Mac computers are so much more stable with no annoying pop-ups. I've never had a virus. I do have Microsoft Office though, which I love. My only complaint is having to listen to all the windows users in my household whine about their problems.
I prefer Windows for two reasons... The first being that most games are developed for Windows, and second being that my favorite C++ IDE, Visual Studio, is a Windows exclusive. That said, many people share many different opinions. In my experience, Windows is more for gaming, and for getting things done. I would classify it as the left side of the brain. Mac on the other hand, is like the right side of the brain. It is more creative, with many programs designed for photo and video editing, as well as other multimedia manipulation. There is no "best operating system," it's all about what your personal preferences are, and what you will use it for.
I use Windows. I've always used it. But I've been hearing a lot of good stuff about Mac lately, especially for people who work in design. So, I'm interested in giving it a try. I'm just afraid it'll be too different. I've heard of compatibility issues.
Both are good. It really just boils down to what your preferences are and what you are used to or what you are ready to get used to. If you like gaming, you should probably be on a Windows, and if you like apps and similar software, then get a Mac. I personally like Windows better because the functions are much more flexible, but I like a lot of the software that Apple developers put out like movie and music editors.