Plasma/Live Images
Try and install Plasma from a live medium provided by several Linux distributions.
Shipping the latest code from Git
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
You can use the Developer-stable version for builds from Plasma/5.x branches or Developer-unstable version for builds from master branches.
openSUSE
Argon and Krypton are openSUSE live images shipping the latest KDE software from Git master (unreleased) for Leap and Tumbleweed, respectively.
Ships Plasma 5.13
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
The developer stable edition builds from Plasma/5.12 branches
openSUSE
In addition to Git based versions there is openSUSE's rolling branch "Tumbleweed" which ships Plasma 5.13 tested with openQA:
Both 32 bit and 64 bit versions are available.
GeckoLinux
GeckoLinux is built directly from openSUSE packages and uses openSUSE repositories.
GeckoLinux NEXT Plasma includes the Plasma 5.13 desktop environment on top of the Leap 15.0 base system. It also includes KDE Applications 18.04 and the KDE Framework at version 5.47.0.
http://geckolinux.github.io/#download-next
GeckoLinux ROLLING Plasma can also be updated to Plasma 5.13.
http://geckolinux.github.io/#download-rolling
Manjaro
Manjaro KDE Edition is rolling release distribution. It provides the latest stable Plasma, KDE Applications, KDE Frameworks and Qt releases.
https://manjaro.org/get-manjaro/
Slackware
Alien BOB (Eric Hameleers) provides an installable Live image for Plasma 5 based on the development tree "slackware64-current". Login account/password are both "live". Use su or sudo to become root (using the "live" password).
Ships Plasma 5.12 LTS
KDE neon
KDE neon builds Frameworks, Plasma and Applications on a continuous integration system.
The developer stable edition builds from Plasma/5.12 branches
openSUSE
The latest released Plasma version is available as a live image as part of the Krypton stable image:
32 bit version and 64 bit version
GeckoLinux
GeckoLinux is built directly from openSUSE packages and uses openSUSE repositories.
GeckoLinux STATIC Plasma includes the Plasma 5.12 LTS desktop environment on top of a Leap 15.0 base.
http://geckolinux.github.io/#download-static
Kubuntu
Kubuntu 18.04 Bionic Beaver development release currently ships Plasma 5.12 LTS in its daily build isos.
http://cdimage.ubuntu.com/kubuntu/daily-live/current/
Manjaro
Manjaro KDE Edition is rolling release distribution. It provides the latest stable packages including Plasma 5.12 LTS, KDE Applications 17.12, KDE Frameworks and Qt.
https://manjaro.org/get-manjaro/
Ships Plasma 5.10
Kubuntu
Kubuntu 17.10 Artful Aardvark, released In October, includes Plasma 5.10.5. The live ISO is available for download, and Plasma 5.11.2 can be installed via the Kubuntu backports PPA.