Here is a user-friendly tool to help decide which Linux distros are a good match for your needs: Linux Distribution Chooser
I’ve recently been carrying around a JP version of a Knoppix Live CD for use at net cafes and public terminals – very handy.
The distros that this test recommended for me include Debian, Ubuntu, and Gentoo, which I have been hearing a lot about but just have not had time to check out yet.