(If there is need to pay for disk, agree) (as easy to install as MS Windows. If it is Linux then can you tell what exactly Linux it is, because there is a lot of Linux systems?)
Initially you might feel hard to work but as and when you get used to it - you will really feel LINUX to be more useful than windows.
Its my favorite Linux distro.
Or you can download and try different distros yourself.
http://distrocenter.linux.com/
If you want to know what kind of linux, open this website:
http://distrowatch.com
There are some comparison for each distros.
I recommend Ubuntu linux for simple download (only 1 CD), but if you want more, try use Open SUSE.