What would it be?
I am planning to split my hard drive in 2 partitions, one carries windows 7 and the other a recommended OS.

It should have


- Great appereance (Toolbars, Windows, effects, wallpapers, icons etc)
- Updated (2011)
- Easy To use
- Powerful
- Rich with Software and cool applications
- Supports hardware drivers


And if you recommend me linux, what version it would be?

Ubuntu, Mint and Fedora are popular Linux choices. All are up to date and should have easy to find drivers.

Also opensuse, mageia and mandriva. They're pretty great distros too.

Installing (or having) a second OS is called dual boot.
There are many OS(s) out there. You could get the Google Chrome OS, The FreeBSD OS or anything that Gormen suggested

Chrome OS didn't seem that cool to me. When I ran it it seemed just like fedora with a customized gnome desktop. The new one looks awesome though, but of course you need specialized hardware to run it...