After decades of Ubuntu use, I've replaced my desktop OS with antiX. It's a minimal Debian system without systemd. Boots to desktop in about 5 seconds and uses only 150Mb of RAM. It's a simple system that I can get my head around easily and administer without unlearning and relearning things all the time like I had to with Ubuntu. It feels fast and efficient, and looks good too. For similar reasons, on the server side, I'm moving from Ubuntu to OpenBSD where I can.

antiX Linux
https://antixlinux.com/