My Top10:
#1 The Elder Scrolls V: Skyrim #2 Mass Effect 2 #3 Half Life 2 #4 Fallout 3 #5 World of Warcraft #6 FEAR #7 The Elder Scrolls IV: Oblivion #8 The Legend of Zelda: Breath of the Wild #9 The Witcher 3 #10 Gothic 2
Yeah I like RPGs and shootybang haha
Top 3 are in order, everything else changes places depending when I think about it
1: Skyrim
2: TLoZ BoTW
3: GTA V
4: The Last Of Us 1
5: Gears 5
6: God of War
7: Forza Horizon 4
8: Final fantasy VII (Original)
9: Animal Crossing New Horizons
10: Pokémon Firered
Honourable Mentions: Team fortress 2, Overwatch, Conkers Bad Fur Day, Horizon ZD, Witcher 3, Fallout 4)
Unhonourable mentions: FFVIIR, TLOU2, Halo 4, Kirby Star Allies.
As you can see, Xbox acquiring Bethesda is pretty huge for me, only thing close to that level is Nintendo. If they acquire a cheeky little Japanese studio to release JRPGs then I’m set. 
I’m splitting mine in to two sets of five
Campaign
Multiplayer
ahhh a fellow Fire Red stan 
I will try to keep it simple and just put one game from my favorite series, it’s really hard to do that because who wants to choose between Super Metroid and Metroid Prime, REmake and RE4, ALttP, BotW and Ocarina of Time or DKC2 and DKC: Tropical Freeze but I’ll do it!
First three games are my top 3 with this exact order, after that it’s all chaos!
Obviously I left out masterpieces like Metal Gear Solid 3: Snake Eater, Silent Hill 2, Outrun 2, DOOM (1993), Metal Slug 3, Panzer Dragoon Orta, Rez, Tekken 3, Mortal Kombat 2, Killer Instinct (2013), Street Fighter 2, Jet Set Radio, Banjo Kazooie, Goldeneye 64, Perfect Dark, Quake 3, Final Fantasy VII, Xenogears, Vagrant Story, Dead Space 2, Prey (2017), Bioshock, Mass Effect, Devil May Cry 5, Soul Calibur, F-Zero GX, Eternal Darkness, Okami, Gears of War, Bayonetta, Super Probotector e.t.c. plus all the other amazing games from the series that I listed but I had to… 
My top 10 
:
Can’t really order it. I’ll do a top 3 which are my absolute favorite and then an unordered 7. But so many to mention
Not definitive. I mean I could put in a few more as hovering around the bottom half like Persona 4 Golden and Breath of the wild. zelda oracles up there too alongside Resident Evil 4.
Made a Top 25 list for anyone curious. Really digging this site. 
https://ggapp.io/CRZYSPZ/lists/crzyspzs-top-25-favorite-games-W4zD04Z2
I am capriciousness personified so my “best anything” is as changeable as the sound of the breeze in the trees, the swoop of the swallow feeding on the wing or the drone of the bee.
Except Jaws, that’s literally the perfect film.
Games though that’s a trickier thing for me to say, I tend to measure “best” not the feeling it generated but the consistency of that feeling, do I still feel able to look back with fondness or enjoy again like I can With Klimt’s “The Kiss” or Dorothea Lange’s “Migrant Mother”. i.e. can I go back to a game and still feel that same love?
Had I the time and had no new experiences to try, here are the games I think I could comfortably go back to and enjoy all over again as if new.
This is easy.
Shoutout to Age of Empires 2 &3, C&C Generals, Rollercoaster Tycoon, Total War Warhammer I & II, Frostpunk, FIFA 07 - FIFA 13, Need for Speed Underground 2, the Anno series and Ori and the Will of the Wisps.
3 real time strategy games, 2 racing games, 1 grand strategy/turn based strategy game, 2 simulators, 1 shared multiplayer game and 1 survival game.
And no shooters! 
Hmm, something about this list…I…I think I absolutely HATE it. Not sure why that is
Ah HA!!! That’s why 
In no order.
These are in no order.
Christ this is hard there are a lot of games I adore, but I made an attempt. If I come back to this a week later my list would probably change significantly.
Here we go:
Honorable mentions: Horizon Zero Dawn, Yakuza Zero/4, Halo, TITANFALL2, Gear of War 2, Sunset Overdrive, Portal 2, Forza Horizon 2