For many years, I’ve used a HTPC with a few different distributions. At the moment, it’s running Debian with Gnome. For me, this is good enough, since the UI allows me to easily do all sorts of computer stuff like having multiple virtual desktops, many browsers, lots of tabs, spreadsheets and a system monitor. Obviously, you need a wireless keyboard + touchpad combo to use this HTPC.

If you’re aiming for a more simplified UX, I would go with something like LibreELEC