I would agree with what champagnemojo said but in my opinion the section where Debian lacks is obsolete packages . Though Debian ships with a wonderful tool apt-get which has the capability to fetch packages from the respective repositories and install them onto the hdd without any dependency problems,but when a person installs Debian for the first time. he has to spend more time in upgrading his system so that his system matches with the latest packages.Example : With a normal Debian Woody install all u get is 2.4 Kernel and an old KDE and Gnome Environments so if i were to get the latest updates . i need to spend more time in installing packages and the the upgradation that would happen to my system would be like from earth to moon because of the old packages that comes along with Debian . Or what i could do is just install the base system and then do a dist-upgrade which would fetch me the latest packages. All in all Debian would suit ppl who have got an internet connection with high bandwidth.

So comparing Debian and Knoppix in terms of the packages u get the latest packages in knoppix so u dont have to spend time in installing a lot of them.