Knoppix is Great
I tried out Knoppix for the first time last night on a new computer which I had not been able to do everything I wanted with Mandrake Linux.
First I was blown away that Knoppix "installed" in less time than it takes for Mandrake to boot! I don't know how they do it, but the hardware detection was perfect and I had a perfectly working internet connected system in about 2 minutes. Additionally, in the system menu there was a an option for "turn on SSH server". I did this, set the password, and in under a minute I had turned my new computer into a Linux server. I was very impressed with Knoppix overall and it has been the best experience with Linux that I have ever had. I will give Yoper a try because I would like a high performance installation, however if I have any trouble in the slightest I believe Knoppix will be an excellent distrubution to use.
The other great benefit is you can try all that I did above without touching your hard drive so there is no commitment. If you like it, you can install what you have working with a single command line command.