Grml is a bit of an unorthodox rescue/live distro, as - if I recall correctly - it offers i3 wm as an option. It also uses zsh instead of bash. Its zsh config is quite nice, so much so, that it was included in the Arch Linux live media (at least in the past).
I've alternately used Grml (debian-based) and SystemRescueCd (gentoo-based) for general-purpose system recovery, network booting to run an imaging process, and several other projects. Thanks to everyone who maintains a "live cd", as we used to call them!
I used it as a desktop for a year or two maybe about 6-8 years back.. Blazingly fast.