Regarding Linux distro’s which has best GUI and most intuitive ?

On a HP Pavilion a839n machine what would be the best distro of linux currently for automated installation and a intuitive GUI for people who have no linux experience? Working on a friends computer – and they have no linux experience so what is the current recommended install for a computer of that age ? It has been upgraded to include 2 gigs ram and a pci graphics card. I have upgraded the machine to win 7 64 bit but had issues with sound and internet. So I’m looking at a linux OS install for this machine. Any recommendations on linux disto for my machine?