My vote goes to Ubuntu-MATE, and its what I install to others in oem mode, so they can pick their own language/user/password on their own later.
Many people have used and loved gnome2 as a linux desktop, MATE is this, with bugs fixed and gtk3.
For newcomers the question comes: How you want your desktop to look like?: Windows like, Mac like, "linux" like? You just launch mate tweaks and have the desktop appearance rearranged with a single click (similar to Zorin).
There is also the Welcome screen; the must have things you need to do right after install. Proprietary drivers? Codecs? Language?, some extra app?, just click the green button and it takes you by the hand step by step. From it, you can single button install things like Chrome, Minecraft or Whatsapp.
Ubuntu-MATE only uses the normal Ubuntu repositories and can optionally use any PPAs you might need, so your support and access to software is the biggest. Unlike Mint, there is no extra layer on top and you don't need to deal with the dangerous Mint updater and certain "features" that make Mint too easy to break for a newbies. It also helps that you get updates immediately from Canonical and not after Mint reviews, and (hopefully) test them against their own changes from Ubuntu.