My favorite overall, they’re community-run, stable, well-maintained, have a rich history of being awesome, and they’re just top quality general-purpose distros. I tend to use Arch for more recent desktop systems and Debian for server systems or older desktops.
NixOS
What I’m dabbling with currently, the concepts here are amazing but it’s a bit of work at first to truly get value out of it. Still, seems to be a good option for my next notebook OS.
Fedora Silverblue (respectively the immutable variants)
Also cool, as is Fedora in general, although with the recent Red Hat fiasco and Fedora’s plan to introduce opt-out telemetry I’m more hesitant now. Some time ago I’d have listed Fedora at the top but now it’s slid down a bit.
Mint
Kubuntu
Easy recommendations for new users coming from Windows
VanillaOS
I like the idea of making it possible to install packages from all distros (they will then run in a distro-specific container). I wouldn’t use it, but it’s cool
Kali
Tails
Alpine
From the more specific distros
Slackware
Honorable mention, because it introduced me to Linux back in the day (yes, I liked starting the hard Unix way). I wouldn’t recommend it these days but it’s kind of like the granddaddy of all Linux distros, and it was awesome in its prime. I’m sure it can still be used today but it’s gotten quite niche.