Live CDs - a way to choose your distro
A Live CD allows you to test-drive the usually latest stable version of KDE SC without the need to install Linux or to change your existing Linux installation. These distributions boot and run completely from the CD and don't modify your hard disks. They can therefore be tried on a Windows computer without risk. All listed CDs are freely available for download.
Kubuntu LiveCD
A live CD version of Kubuntu Linux, Ubuntu's KDE Plasma Desktop option. Kubuntu also offers the Kubuntu Active Technology Preview, a preview of Kubuntu using the Plasma Active tablet experience.
Fedora
A fast paced distro targeting users who want the latest and greatest available in the world of FOSS. Fedora KDE usually has the latest stable version of KDE in the repositories, and beta versions are usually shipped via supported extra repositories.
Mepis
Based on Debian, Kudzu by Red Hat. The disk also offers installation to hard drive.
PCLinuxOS
Based on Mandrake (now known as Mandriva).
Slax - Live CD
Based on Slackware. With modular structure and pseudo read-write CD filesystem. Slax can be run from a USB Flash Drive. Slax has no graphical installer; if you want to install Slax on your machine, you must follow the simple instructions in the Introduction document.
openSUSE Live-CD
It allows to try openSUSE with KDE SC and install it to hard drive.
Aptosid - successor to Sidux
Aptosid is an operating system based on the Linux kernel, Debian's branch (called "Sid") and many free and open source applications.
Linux Mint
Linux Mint is based on Ubuntu and Debian and is aimed at beginners. There are versions of Linux Mint for several desktop environments. Be sure to get the KDE version of the Linux Mint Live CD.
Chakra
The Chakra Project is a promising newcommer. Originally based on Arch Linux, Chakra is focused solely on KDE workspaces. It is possible to install third party applications, as well.
Mageia
Mageia is a community based distribution. It is a fork of Mandriva.
Netrunner
Netrunner is based on Kubuntu with it main focus on KDE, and aims to be complete operating system for both beginners and experts.
ROSA
ROSA, a Russian company, offers their enterprise solution ROSA Marathon 2012 for download. The new ROSA Desktop.Fresh edition is aimed at regular desktop users.
KXStudio
KXStudio has a focus on audio and video production. Currently, it is based on Ubuntu and has KDE as its officially supported desktop.
Sabayon
Sabayon is a "rolling release" distribution, meaning that you install once and have your system upgraded as new versions of installed software is added to the distribution. Perhaps not the easiest distribution for users new to Linux.
Pardus Live
Pardus is a Turkish distribution based on Debian. Previously Pardus was a well regarded KDE-based distribution, but the project has been dormant for more than a year. The new version published late last year (2012) seems to depart significantly from previous versions. Currently it is only available in Turkish.
Homepage
OpenMandriva Lx
OpenMandriva Lx aims to be easy to get started with but also cater to the advanced user. OpenMandriva is a community project.
Korora
Korora aims to be easy for new users, but still useful for experts. It is a community project based on Fedora.
Kwheezy
From the project site: Not so much a distribution based on Debian, but rather "a well configured Debian KDE installer". It is designed to give you more out-of-the-box. To be easier for Linux or Debian newcomers.
Porteus
Designed to run from a USB flash drive, Porteus is small and fast. Porteus is a community project based on Slackware.
SuperX
An Indian project, SuperX is based on Ubuntu. From the project site: SuperX uses a tweaked version of KDE and is aimed towards beginners, casual users and business looking for a well supported user-friendly Linux OS.
Bridge Linux
Based on Arch Linux. The installation and setup procedure is not as simple for new users as most live systems.
New Live CDs and DVDs are becoming available all the time. If you've heard of a distro and think you'd like to try it, do an Internet search for it. You may well find that a Live CD is available.