Linux OS has lots of flavors. Deciding the right flavor (distribution)
is sometimes confusing.
To list some, we have Fedora, Knoppix, SUSE, Mandriva, Debian, Slackwave, Linspire,
Freespire, Ubuntu and lot more ..

    I have worked on two distributions, Fedora and Ubuntu .
Out of those Ubuntu linux attracted me a lot.
Excellent GUI, Simple installation, Lots of softwares available online (ofcource
opensource), good support. Everything that you expect from a Desktop OS. Also as
it is a linux distribution , So You get powar and security of linux .

The Ubuntu promise: (from official ubuntu website) 

• Ubuntu will always be free of charge, including enterprise releases and security
  updates.
• Ubuntu comes with full commercial support from Canonical and hundreds of companies
  around the world.
• Ubuntu includes the very best translations and accessibility infrastructure that
  the free software community has to offer.
• Ubuntu CDs contain only free software applications; we encourage you to use free
  and open source software, improve it and pass it on.

Also you can request for a free CD from ubuntu.

Goto https://shipit.ubuntu.com/ if you want a ubuntu CD for free. (it will take
4-6 weeks to deliver).

So start your journey of ubuntu world ...