This is an odd one, as it would really depend on the person more so than the game.
Mostly these days, as a parent, I’m dealing with other parents, and if I was to give a game to them, I’d likely give No Thank You, Evil!, since it’s targeted at families. I like the production values, although as I’ve said before, I’m not thrilled at how combat focused it is. Nevertheless, I think that it’s a good starter for kids to get into gaming as it’s very pretty and looks do matter in the sense that when I show it to kids, they gravitate to the artwork. The setting and character building are also lots of fun.
If I was giving a game to an adult who did not game, I’d likely give them either the D&D Starter Set (5th edition), again because it’s a great introduction to gaming. However, if it was for an adult who was already a gamer, I’d likely give them Savage Worlds because you can play almost anything with it.