A gui installer with which you can download and install all the packages from sources added by you. So you won't be restricted by the package selection of knoppix.... knoppix has too many packages that you won't use if it's installed on your computer. A net-installer would be great for all the linux noobies- you can see what you are going to install and get the latest of everything you want to install.

Hope the post isn't too messy.