Pathetic list, I must admit.
Stardew Valley? LOL
Halo: Combat Evolved? WUT?
Doom 2 ? Hah.
World of Warcraft? GTFO
Thief 2? Nah
League of Legends? Hells to the no.
Most of these could easily be replaced by "honorable mentions" which you included, which are FAR more deserving. And there are some, which had way more impact on gamers (and still do) which did not make the list.
You were suppose to create a list of games that "every gamer" should own.
Why on earth should anyone own Doom II, or Star Dev for crying out loud?
Seriously.
Honestly this list isn't too bad. But by far personal preference.
Stardew Valley while great fun is most def a honorable mentions type of game, along with world of warcraft, Thief 2, and League of Legends.
Halo:CE on the other hand is a staple of the FPS world. The Story and gameplay, with the pacing and atmosphere that was presented. At the time of release was just never seen in a video game before. The original Half Life showed what a more scripted story could do to a game. But this game just set the bar for everything that followed. On consoles it defined the controller layout we still use today, on PC it offered on the best multiplayer experiences for the time. I personally spent hours playing halo ce online on the computer, before halo 2 would explode on the xbox. The Story is still great to this day. I feel the only people that look down on this game are people that never played it and got to experience it in the time frame it launched. Just cause one may hate xbox or how overrated the halo series got later in life. This game deserves all it, as historically it was the game that defined how the genera would work even 2 decades later.
Doom 2 is a classic. I can understand that some people never got to experience DOS and windows 3/3.11 growing up. I did. Doom 2 is a classic, takes everything from doom and refines it. Honestly I do like some of the chapters from the original doom more, but doom 2 is just ton of fun even today. GZDOOM makes playing those old Doom games on modern system a breeze, and with come keymap changes and enabling mouse look. The game plays like a modern game. I love it and still boot up doom/doom 2 every few years for some classic fun. There are a lot of doom clones that were also great, like star wars dark forces or duke nukem. But for 90's era games there are so many great games, like Fallout 2, System Shock 2, and Diablo. Along with many more. Hard to pick the best. But the game that made the biggest impact in the gaming world. Doom/Doom 2 from a historical view fits that mark.
Company of Heros should have been on this list. It is the best RTS game ever made hands down.
Bioshock or Bioshock infinite should have been on this list as well.
Honestly IMO the last 10 years had a lot of quality games, but nothing I would ever put on a list for "Must Play" or "Best of a Genera". Other than two or three, Bioshock being one. Portal 2 being the other. Mass Effect 2 would be my Third, and up there on my list. But is not a perfect game.
Witcher 3- Great, and maybe even list worthy. But IMO you pick this or skyrim for a list, not both.
BoTW- Honestly would be list worthy if it had more content. Only a few enemies in the game, and no epic side quests.
The PS4/XB1 generation has been the worst I've ever experienced. Sony had some decent exclusives like Spiderman, but that game isn't even list worthy. Great fun, and enjoyed my time with it. But overall had a fair many flaws.