I personally like Slax, for several reasons, chief among them is its ease-to-remaster the system. You can take ready-made Slackware pkgs, run a single script to create a Slax module, put the new module in the /modules sub-dir of your ISO and reburn. It's about two or three steps more involved w/ the autoconf+automake-confg'd tarball, but still easy.
I have many live CDs and love the idea. Is there something else out there that's comarable ?