I daily drive Fedora and I think it has the best Gnome desktop.
But in terms of "best at what they do" I'm blown away by Mint as an apporoachable easy to use "just works" OS. It instantly became my recommendation to new linux converts. Everything is easy to set up. It's remarkably user friendlly. Good software store, flatpack support out of the box. Brilliant hardware support. I like the aesthetics as well.
I have an old Core 2 machine and I tried to get every potato grade distro running on it. I tried Puppy, and Linux Lite, and AntiX and all the "this will run on your toaster" type distros and had problems with every one of them. Mint XFCE installed no problem. It ran beautifully. I pressed my luck and installed a Quadro K620 and an old firewire card (trying to back up old Mini-DV videos). It handled ancient hardware perfectly. Butter smooth 1440p desktop computing and light video editing on an 18 year old machine.