Don't reopen that wound.

100% this. All of those awful Sonic games. I didn't even like the ones that some did like Sonic Adventures, and don't get me started on Sonic 4 yuck. Sonic Mania on the other hand felt perfect and played like a true Sonic game. I also got a sweet physical version on Switch with a reversible Mega Drive cover. The nostalgia was next level. 

Fair enough!

For moi....

- Super Mario Galaxy. After the bland tedium that was Sunshine, so lacking in Nintendo's usual magic, Galaxy recaptured that sense of wonder and joyous ingenuity that characterizes the company's best games. To this day, it remains the #2 best game ever made in my opinion.

- Twilight Princess. It returned Zelda to what it should be; an epic, dramatic fantasy adventure with a tasteful measure of darkness, a sort of video game equivalent to what Lord of the Rings is to literature and film.

Forgot to mention Animal Crossing. It was painful to have an Amiibo game on the Wii U, a house designer game on 3DS, and a barebones mobile game during a seven-year wait for the main event. 

I'm probably dead wrong about development teams and resources on the spin-offs, but I feel we could've gotten New Horizons in Q3 2018 - Q2 2019 if not for all the shifted focus on spin-offs and to some extent the Welcome Amiibo update of New Leaf.

Doom 2016 is also up there in my book.

Doom 3 was not a bad game, in fact it was quite good for what it was, but as a result of its much slower pace it lost the sheer fun factor of the originals. The 2016 reboot brought the excitement and energy back with a vengeance, not only recapturing the fast-paced arcadey action of the first two games but improving on it with its "push forward" combat that incentives aggression and speed and is one of the most satisfying combat loops of any FPS ever in my opinion.

For me, probably Super Mario Galaxy. Don't get me wrong, Sunshine is a pretty damn good game. Still better than most games out there. It just felt...not quite right. It didn't live up to the standard I was expecting. I think FLUDD was a mistake. I thought the best parts of the game were those little levels were Shadow Mario would steal FLUDD. Those parts actually felt great, and it made me just wish standard platforming was in the rest of the game.