It's free.
You probably wont get any viruses.
Lots of free software.
Very customizable.

I haven't used Mac OS in a long time, but from what I have heard there aren't very many games. I use Linux now and there aren't very many great games either, mainly just generic things like poker, chess, ect.

You might be able to Windows games to work on Linux with WINE, or you could buy Cedega or Crossover games (which can also run Windows games on a Mac).

Could you give me some more info? And would I really need Linux, or even use it for that matter?

Linux is free-- so it would cost nothing to try.
Would you need it??
probably not-- but it's fun to explore.
Ubuntu is a good starter-- for Windows-users
Ubuntu Home Page | Ubuntu
extensive help-- their own forums-- with a newbie section-I know you are no Noob-- but Linux is a little different
Ubuntu Forums

My 2-cents worth.

Linux is extremely fast compared to any other OS (except maybe Unix variants), it also gives you full control over the system, where as I feel with Windows your control is limited. I'll give you a quick example; in linux if you plug in an external hard drive you can partition it any way you like, in windows you need various reg changes to do the same thing and face the possibility of damaging you system.

Also the file system is journaled - this means fragmentation does not occur and as a result the system is much more stable - FAT is prone to fragmentation and as a result can suffer from 'slowness' - even following fragmentation.

Also as linux is a community based operating system, any problems or security holes are fixed VERY quickly, unlike Windows where your relying on a single team of engineers to fix problems with the sytstem).

Linux as a whole is becoming much more user friendly, and although still isn't up to par with Windows I believe in time it soon will be. Linux currently has a rather large hold over the server market owning roughly 60% of servers worldwide and the reason behind it is the examples i gave above - community based security, speed and a full control over the system.

Whilst in my opinion it is a good 'thing' to learn, most people will simply choose Windows over linux simply because of the challenges they face, installing it with unspoorted drivers is hard enough, people who use wifi are almost bound to run into problems. Once it's setup and your a regular user though the advantages become obvious. One of the down sides is GPL - linux runs a general public license which essentially means all the software has to be free - take a company like realtek, they make sound cards, as they refuse to release software for free it means the linux community has to build their own drivers in order to get specific hardware working, without a working knowledge of the hardware in place it will sadly never be as efficient as realtek making the driver themselves (the case is similar with wifi cards).

Someones already suggested a trial CD - thoroughly agree with this, give the operating system a try and if you like it, install it, if nothing works and you hate it then stick with Windows. I'd recommend the following linux based OS's: opensuse, ubuntu, and mandriva also if you like hacking, try backtrack.

Oh, also installing linux will be a hellovalot easier than installing a hackintosh system, the hardware needed is VERY specific - right down to specific processors.

I think it is illegal to run MAC OSX on a PC by the way.

Based on what?
If he owns the license for the OS-- he should be able to install it where he wants to...