I have been installing and using a wide variety of linux distros over 2005. I thought this might be a good time to mention linux with the present virus scare windows users are experiencing right now.
The winner is PCLinuxOS.
Runs good as a live cd and a few mouse clicks will install it to your hard drive if you wish. There are downloadable iso images for those with older Nvidia video cards, newer Nvidia cards, and an Ati version. This gives you 3d acceleration right out of the box so can play tuxracer right away. You can also choose a lite version without OpenOffice. OO can be installed via synaptic at a later date easily.
PCLOS comes with the necessary codecs, flash, and java so you can enjoy multimedia without jumping through hoops. I have it installed on a laptop with wireless and wifi works perfectly.
Updating and installing/uninstalling software with synaptic is a snap.
I am tickled pink with this operating system and rarely need to use windows at all.
O ya ... Its free.
I have to give honorable mention to alinux (canadian fellow builds and maintains it), Kanotix, and Mepis. Ubuntu is very popular but is lacking in many ways.