1. EarthBound.
Quite likely, the universe will implode before this is replaced. I've seen many poor attempts at emulating it, including such games as Undertale, but nearly all of them have a basic misunderstanding of what made this game good to begin with. It wasn't just the quirkiness; it was the quirkiness of America as seen through a set of Japanese eyes and the resulting love poem.
2. Breath of the Wild
I am very hard to please when it comes to Zelda games, and for a long time none managed to capture me quite like Link to the Past did. I admit I didn't even give some of them a chance, but that was due to not wanting to buy a Wii U or Wii. Then came Breath of the Wild.
Plus, I hate the time travel mechanic of OoT. It irks me the way it's handled.
3. Super Mario Odyssey
Oddly, despite the fact I played a lot of Mario games, I mostly use them for vegetating. They don't really grab me that well, and for the most part this slot was filled by Diablo 2. I have to admit the combination of modern mechanics and nostalgia got this one an unusual place.
4. Final Fantasy 6
Sorry, but I've not seen any Final Fantasy after this manage quite the same epic scale of storytelling. This one even beats 7 for me.
5. Mass Effect
The sequel and third in the series never managed to capture me like this one did.
6. Witcher 3
I have to admit, I like this one. It takes everything I liked about the prior two and improves on them.
7. Ogre Battle and StarCraft 2 are equal on this slot
Originally, this slot was Warcraft 3 and the original StarCraft. Then StarCraft 2 came out and replaced StarCraft. But, lately, I've been replaying the Ogre Battle series and remembering what I liked about it. This may change with the upcoming Warcraft 3 remake.
8. Stardew Valley
I like farming games of the Harvest Moon style. They're relaxing. And this one massively improves upon the formula.
9. Endless Space 2 and Stellaris are tied here
This used to be GalCiv 2 and Civ 5, but I don't play either much anymore. GalCiv 3 isn't really capturing my heart, and Civ 6 is increasingly going from "annoying" to "are your devs on drugs?" with how badly implemented the expansion mechanics are. These two ended up filling the niche; I get my quirky, personality-filled gameplay from Endless Space 2 and my mushroom men are dominating the galaxy in Stellaris.
10. Pathfinder: Kingmaker and Pillars of Eternity 2 are tied for this spot
This used to be Baldur's Gate 2, but I like both of these games more right now. Plus, I'm irritated that DnD is floundering in the video game department while the ever-mismanaged Pathfinder is actually beginning to make some headway.