1. Low cost: You don’t need to spend time and money to obtain licenses since Linux and much of its software come with the GNU General Public License.
2. Stability: Linux doesn’t need to be rebooted periodically 
3. Performance: Linux provides persistent high performance on workstations and on networks. I
4. Network friendliness: Linux was developed by a group of programmers over the Internet and has therefore strong support for network functionality.
5. Flexibility: Linux can be used for high performance server applications, desktop applications, and embedded systems.
6. Compatibility: It runs all common Unix software packages.
7. Choice: The large number of Linux distributions gives you a choice.
8. Fast and easy installation: Most Linux distributions come with user-friendly installation and setup programs.
9. Multitasking: Linux is designed to do many things at the same time
10. Security: Linux is one of the most secure operating systems. “Walls” and flexible file access permission systems prevent access by unwanted visitors or viruses.

All the advantages are given in the link on top but few of them which i found cool are given below

1.  No Mystery Extensions  The Windows systems are loaded with hundreds of mysterious files.

2.  Bootable CD-ROM  Starting up from a CD-ROM makes the software installation process easier. On a Macintosh, the computer can easily "boot" (start up) from the system software located on a CD-ROM. If the software on the hard disk becomes corrupted somehow, you can easily insert a CD-ROM and get going again.

3.  Issues with DLL  The numerous "DLL" files that Windows applications install all over the hard disk drive can conflict with each other and cause serious system problems.

Windows is the most popular operating system and has a very user friendly GUI. It is also very easy to operate. I am not against Windows but security flaws in the OS has compelled me to rate it last. AS you can check in the thread above.