My list would be Pong, Tetris, Pac-Man, Donkey Kong and Super Mario Bros, but maybe I'm a bit *too* much of an Oldfag.
@ChristiJunior
I don't count ancient games as iconic, since they literally have no alternatives. Yes, people did grow up with them, but it's not about them being iconic as much as people having literally nothing to put in that place.
Nah...
I will call Minecraft, Pokemon, League of legends, Tomb Raider and World of Warcraft.
All of these games have a cult of their own, as well as iconography unique enough, that normies will recognize them on sight. I haven't seen a pong obsessed fan in a while. (Tetris is the only candidate from your selection, that I would accept, since it's cult is somehow still alive.)
@ChristiJunior
Also, Mario is weird.
He should not be popular or iconic by any stretch, but Nintendo had been pushing him more, then legacy media are pushing for sleepy joe. With that kind of intense marketing, you cam make a mummy into a president, so of course, people know Mario.
https://en.wikipedia.org/wiki/List_of_best-selling_video_game_franchises
@ChristiJunior
Ok... so, what Modern Mario games should I first buy for my emulator... 
I mean emulator... 
I mean emulator... 
I mean emu
You can emulate the hell out of the Galaxy games, because Nintendo decided to be cute and only make Galaxy 1 available as part of a shitty collection that was only available for a limited time to cause artificial scarcity, and didn't make Galaxy 2 available at all.
Jury's still out of the Paper Mario: TTYD remake, but so far it looks to have been hit pretty bad by Global Standards, so the GameCube original might be another good Seven Seas candidate.