As a Live CD it's one of the best, with plenty of good software and good hardware detection.

For some reason though, between 3.9 and 4.0 .. something happend to sound and I always have to run alsaconf to make it work.

HD installer simply craps out now (4.0 beta used to work, but 4.0 release installer just leaves the bootrecord in a mess if you don't install it on the MBR .. which no sane person should do anyways )

I always load it when I have to use a "windows" only PC(I don't have the right to install software)

Well, this is a valuable rescue cd for me (although others exist). It is a great distro and that many people use its kernel configuration to start with building their own kernel should say something about it....
Once a friend aked me to save his documents from his laptop while it was not booting (cause he installed 2 anti-virus progs!!). Guess what, the documents were located in the windows partition and there was no way to format it without loosing the documents. I never had the great experience with the windows internals (wondering why? :D) to fix the registry s**t so the solution was right there....
Its also good for newbies to have their first touch with Linux because in most cases it's just working and they can't change anything important.
Many, many, many other reasons that make this live CD a great OS do exist but my free time gives me this much to say...
Last words: Recomended for everyone

I recommend everyone go out and get a copy of Knoppix Hackes by Oriely. You would not beleive the uses for the knoppix cd or dvd. From zeroing and overwriting a hard drive , to ghosting one drive to another, repairing grub or lilo, and using knoppix config files to repair an installed nix with a messed up one.

Also you can use Knoppix to install a base Debian system that you can upgrade to Debian testing or unstable.

I found the installer no worse than previous releases.

What else do I have to say? KNOPPIX can be used for pretty much anything. It's my favorite Live-CD distro.

I had a chance to try this and must say it is quite impressive. After spending days messing around with my Mandrake 9.0 load and manually configuring my smbclient to connect to my windows network shares I was amazed when I fired up this distro and it jumped onto my network and saw my windows workgroup and could browse shares with ZERO commands from the terminal.. Very slick looking interface and TONS of apps for a 700MB CD!

It makes a great Virus free PC. Disk is read only and reboot fixes any infection. PARTD utility works great for resizing partitions. TETHEREAL already installed as well as Kismet. Version 4.0 can read NT partitions. KWIFI autodetects and installs many wireless cards as well. (not broadcom chipsets)

This LiveCD distro is really nice... Find the wireless networks with Netstumbler on Windows, and in a snap switch to Knoppix and 0wN3 it :-)

I use gentoo and debian at home, and redhat at work. i support various windows systems for a few small companies, and i never go to a job without my knoppix CD. the simple saviour to every dilemma. with a knoppix in your pocket, your clients think you're a legend.