If you have doubt's about choosing the best Gnu/Linux distribution to you, this site can help.
It will ask you some questions, inquiring you about your experience and preferences with Linux.
If you wanna see some screenshots of the different distros, go here!
PS: if you make the test, let me know about the result!
I got Ubuntu, Debian and Xubuntu! I already use Ubuntu :D !
Links:
»Linux Distribution Chooser: Homepage
»Linux Screenshots: The coding studio