Gateway games generally have simple rules that are easy to teach non-gamers in order to attract new players into board gaming as a hobby. But they are great even for seasoned gamers to start off your game night or play between heavier games.
A Fake Artist Goes to New York
7 Wonders: Duel
Imhotep: The Duel
Lost Cities Card Game with 6th Expedition
Clank!: A Deck-Building Adventure
Dominion (Second Edition)
Sushi Go Party!
Harry Potter: Hogwarts Battle
Isle of Skye: From Chieftain to King