For first time gamers, hand-eye coordination and pattern recognition are some of the larger hurdles. I find that because of this slower games and especially turn based games tend to be fantastic choices for first time gamers. I also find that first person games are sometimes disorienting for new players so I would personally stick to isometric games instead of 1st/3rd person games. And there are a couple games in this list I usually see non-gamers or boy-/girlfriends of gamers playing:

Civilization V or VI

The Sims 3 or 4

X-Com: Enemy within

SimCity

Cities: Skylines

Anno 2070

Company of Heroes

Divinity Original Sin

Pillars of Eternity

Baldur’s Gate 2

Planescape: Torment