Since you said it is for Desktop, lets throw Redhat and Centos away from this list.
If you want to just use linux for your day to day operations with fancy desktop environment, cool visuals, less installation time, dont (want to) know how to compile things and need everything works out of the box, then go for “Ubuntu” or “Fedora”
If you really want to know “How Linux Works” in the first place, need a faster system even with lower system resouces, ready to invest time in hand picking the packages you like and have a highly customized system, then your best bet is “Gentoo”.
By the time you finish installing Gentoo with necessary packages, you would have already become an expert and start to hate the other OS’s especially Windows. 😉
Not to scare you, but Gentoo usually takes 3 days to a week to complete the full setup, be prepared and buy an additional coffee mug 😉