Linux Live CD: Knoppix 6.2
I downloaded this the other day and way very impressed. Ubuntu is my favorite distribution on Linux, but I was very impressed with Knoppix.
The Live CD is a breeze to use and perfect for someone who wants to try it out without putting it on their hard drive. Just download the Live CD version, burn the image to a CD, then boot from it. The OS will run without installing to your drive.
The standard install includes Openoffice apps, Apache, PHP and MySql. It also comes pre-installed with the Compiz 3D desktop. The 3D desktop runs kind of chunky off the live CD, but it is tolerable. Gotta love the 3D Cube!
I think Ubuntu is the best for someone coming to Linux from Windows, but Knoppix is definitely worth checking out.