I am an avid mac user, however, I don't want to seem like the stereotypical 'PC hater'. I respect and use both Mac and Windows and I understand the appeal of Linux. I have been using mac since the time they still had floppy drives and have only ever had one Windows machine: a Windows 95 laptop. Obviously, this doesn't put me in the best position to evaluate both sides but I do regularly use Windows away from home.
My personal opinion is that Macs are the 'ideal' machine and OS for general use and being 'creative'; they are ideally suited for personal use at home. However, the lack of expandability is a problem, unless you opt for the expensive Mac Pro. Windows, in my opinion, are in their element in the workplace where, in most cases, a Mac simply wouldn't cut it and would be too expensive. Also, I can't visualize a Mac being used to drive machinery or getting 'dirty', as it were. The only workplace that Macs are really the better solution is in any of the design trades, i.e. Graphic Design, Web Design. It is this division that separates the two systems and make them individual. I must admit that I love the Mac user interface and the real ease-of-use; but if I had been using Windows for this long would the inverse be true?
In terms of bundled software, Macs really shine through and, despite what some say, there is software available to do most things. On Windows, however, the gaming is far superior to anything an average spec Mac can offer, partly due to the expandability of the systems. The 'Boot Camp' software on Mac is also particularly helpful as it really opens up the opportunities for what some call a 'closed system'. Dual-booting eliminates the need for two separate machines. We Mac users may act as though it is some amazing new tech, but I know that it has been readily available in Windows and Linux for ages.
The Mac design is iconic and links pretty well with the GUI. With Windows, the quality of the design is really only limited by how much you are willing to spend on the exterior looks; the same applies to Linux machines. In some rare cases, those of us who argue that 'Windows Vista copied Mac OSX' are correct, but only in a very few examples. I don't like to think that I have been 'brainwashed' by the Apple corporate identity and I hope I have not become one of the stereotypical Mac users that despise all things non-fruity.
I have mentioned Linux very little as anything I say would likely be misinformed and not give a real representation of the diversity of the options offered.
Overall, I am a Mac user, but I understand the necessity for the use of alternate systems and the advantages of using them.