Apple computers do music production better.
Windows computers do more games.
Apple computers do movie editing better.
Windows computers are easy to mod and customize.
Apple computers work efficiently to provide more power for less hardware.
Windows computers do accounting and database management better.
This is actually an interesting point, and actually demonstrates a lot of common urban legends about consumer computers.
First of all the bit about doing music production. It's really a matter of picking which tool you like more. This is true for all of the cases mentioned here, but we'll just talk about it in this context and you can apply it to the rest yourself. If you're doing carpentry, one person might use a bandsaw to cut something, another might use a handsaw and then sand down the edge if it's rough, and someone else might use a circular saw. What's the "right" way to cut a piece of wood? Well there's not always a right way to cut a piece of wood. Sometimes it *is* clear what tool you should use, but at the end of the day, if everybody cuts a piece of wood in half using their preferred method and they all look the same it doesn't matter.
It's the same with music. It doesn't matter if you're using some free software on a linux box, garage band on a mac, a $3000 piece of software running on a windows computer with a $2000 microphone, or an audio tracker running on an old amiga or comodore computer. If you're a musician, and you're good at using the tools of your trade, the tools you pick to make your music will not factor into the quality of music at all.
The bit about games might be true. You can run a lot of games in wine, parallels desktop, dual-booting into windows, or just buying a second computer just for games. It's not a great argument for getting a PC vs getting a mac, and it's also slowly changing since more games are coming out on both systems because macs are starting to become more popular as desktops and laptops, to the point where it's worth producing two versions of the game. In the future it probably won't even matter which OS you have.
Which operating system does movie editing better is just silly. Back in the day (mid 90s) if you wanted fancy editing you're looking at SGI or Amiga computers. Nowadays you'll probably find that most professional movie editors just use whatever computer they like and are most comfortable with, while all the special effects and animations are probably being rendered on a giant distributed rendering farm running linux.
Windows computers being easy to modify is kind of given. Of course the computers are easy to modify, most PC manufacturers generally don't solder their hardware in, then hot glue the case shut and screw it together with security screws like Apple does. But some do, especially on embedded systems, and you'll find that these are just as hard as their cousins made by Apple. The benefit of not allowing you to put whatever hardware you want in the operating system is that it's more stable though. I would guess that 9 out of 10 blue screens on Windows PCs are from poorly written, corrupted, or misconfigured video drivers. This will never be an issue on Apple computers because they don't need to make an operating system compatible with every single piece of hardware in the universe, just the hardware they want in their computers.
The bit about being more optimized for energy efficiency is iffy. I could probably build a PC with an embedded passively cooled processor that underclocks itself when it's not being used, an extremely efficient power supply, and configure the power management settings so that the hard drive and monitor turn off after ten minutes of not being used and then put the computer into sleep mode, then hibernate. It would probably be more power efficient or at least on par with a comparable Apple computer but I have no evidence for this. The point is you can custom build a PC for any specific application you want. You can't do this with Apple products. I can tell you there are probably very few Apple products in industrial settings. There are probably more Windows computers here, although I would argue that there are better operating systems to use in these cases.
As for doing database management better, I don't know where you got that from, but I can promise you outside of the occasional office running access databases (which from what I've heard are slow and a nightmare to deal with), they might be using an SQL database or Oracle Database, which will for the most part run on a variety of operating systems.
I've heard the "Macs are better for artists" argument since I was in elementary school. I lived near Silicon Valley then, and I've had everyone from classmates, teachers, and other adults tell me it was the case. I accepted it then but I don't believe it now. Not only do I think they're not the best choice now, I don't think they were ever the best choice. Back when I was in school, an SGI or Amiga computer would have blown both Apple and IBM computers out of the water for movie editing. They were 500 billion times better, and according to wikipedia, between 1995 and 2002, every movie nominated for the Academy Award for Distinguished Achievement in Visual Effects was made on an SGI computer. Both companies are basically out of business now and the bits that were spun off and purchased by other companies aren't making computers anymore.
Bottom line is, they can both do about the same tasks now and you can buy comparable hardware for both. There are some situations where buying an Apple computer is not an option because Apple does not manufacture a computer that can be used for that process. In every consumer application though, you should buy whichever you prefer. I stick to Windows PCs because it's what I'm familiar with and I believe I get better value for my money. This is my belief however, and I could care less what other people use.
