As a Linux advocate, I am frequently asked by all sorts of people which particular brand of Linux is "best" for a new user.
It's a deceptively simple question, and if you ask ten different nerds, you'll probably get ten different answers. If you're lucky (and you don't ask a ponytail) you won't have to
listen to endure a forty minute diatribe about how everyone should be able to modify software however they want, and how much "winblows" sucks, including several highly-technical and detailed reasons to support this claim.
Whenever someone asks me, I typically answer something like, "The best one is the one that works best for you. As a new user, I suggest something easy to install configure, like Ubuntu or Fedora. Ubuntu is my distro of choice, and I especially like how I can take a live CD into the store and test out hardware with it. Also, you're standing awfully close to me, man. So could you back off?"
There's a great discussion at Slashdot today about this very subject. If you're interested in trying Linux out, and you read it at +5, you may find some information that's really useful, or at least entertaining.