Must have another go with Slackware - it just hasn't clicked for us in the past.
Slax, ummm.. maybe, but... dunno.
Similar with Arch - we successfully built Arch with LXDE for the Raspberry Pi in the midst of the systemd transition when the docs were out of sync, and it worked OK (eventually) but no love grew.
Expected more, somehow - must be doing it wrong.
SuSE 10 used to be *the* distro of choice when it was new and shiny, but the package mungler ate our nVidia drivers once too often (which we needed for OpenGL CAD, for work), so the early 'buntus then became our default; Xubuntu was a good compromise, Ubuntu Netbook Remix was excellent on our cheap hardware, and then Unity crashed it all for us bigtime.
Four out of six machines would no longer boot reliably, and besides I'd tasted Geubuntu/OpenGeu before it ceased.
Linux Mint was popular for a bit, but LMDE had irregular update problems on our systems, and the excellent Mint FLuxbox CE just ceased to exist. Understand that Mint 17 is top notch now, but lack long term experience of it, and Cinnamon is just, umm... nice? No deep passion felt for it here - ymmv, of course!
Similarly Debian feels wonderfully worthy, and (unlike others here) I just love the apt tools. Might have been yast/yum which drove me to this!
In between mainstream workplace distros and Knoppix on USB which I use daily, I really love Puppy Linux and SliTaz too. Small really can be beautiful and fun to use.
The truth is, I was something of a distro hopper (who has never got on that well with RPM distros after the SuSE fiascos).
Thought I would stay that way to the grave...
Until Bodhi Linux launched.
Now I hop no more.
It just does it for us, and for (almost) all our posse. The combination of a carefully tweaked Enlightenment desktop backed up by the 'buntu repos has Just Worked for us and for the dozens of others we support since version 1.0.
Running Bodhi alongside Xubuntu LTS on identical hardware both were near-flawless over the first year, but Bodhi would spank Xubuntu on frugal use of memory, response time, desktop options/configurability and ability to generate serious bling if needed. Love XFCE though I do, I greatly prefer the E desktop. It does the job so efficiently, and is a work of art when used wisely.
But the real overall winner must be Gnu/Linux as a whole.
We are so fortunate to have this wonderful array of wond'rous distros to choose from - all thanks to the devs!
Respect to -anyone- who manages to release -any- distro, and to the giants upon whose shoulders we stand.
Looking at you, RMS, Linus and friends. Long may you prosper!