I got a Knoppix 5 DVD months ago and finally got it working several days ago after finding some hardware problems.
I have little experience yet, but it's a huge 10 Gig distro. It seems that they bundled every software package available into it. It also includes a number of user interfaces ( KDE, Gnome, etc) and the ability to switch between them on the fly, cool!
I like the "Initiating start-up sequence" during boot-up. That inspired the VoiceOFAmiga.lha collection on Aminet.
I'm impressed. I'll be exploring this for a long time. Free modern OS and software that runs fast on old, inexpensive hardware. Hard to not like it.