Puppy linux seems like its still one of the more unique Linuxes around. Its my go-to when I need to do a recovery for family/friends and seems to almost work with any system. If it can, it will load its entire system into the RAM and go to town. If it cant. then it will act like a live disk...but you can "save" the OS multiple different places. Its a fun little OS.
Ha. Was about to say the same. Running EasyOS on one ofy extra partitions for testing, and I end up using it as semi-daily driver often due to how light it is. Great on a USB key, too.
It is also somewhat unique, on top of other Puppy distros.
I ran Puppy as a daily driver for about a year before I finally got a new hard drive for that computer. It's surprisingly robust for such a tiny footprint.