Ergasiophobia's Journal: Best Linux?

Recently my old Dell inspirion 1100 just got too old and and decrepit to be of any real use, so I got a new computer. I'm interested in installing Linux on it, I have two separate 20Gb hard drives so I have one to experiment with as I'd like to keep the other as a backup. So I ask you, the slashdot community, this: What is the best distribution of Linux to "start out" with, and why?