Portal 1/2 - Still sticks with me as one of the greatest games I've ever played.
Iconoclasts - Made by a single guy over 7 years, it is nothing short of a masterpiece. He absolutely nailed the art, the music, the characters, the game design and the story, a truly remarkable title.
Furi - The best boss rush game I've played. I love the atmosphere and the feeling of the whole experience. Very fun and challenging, great visuals and character designs.
IWBTG - I can't say much here. Objectively certainly not a good game, it manages to defy every game design point but it is extremely dear to me.
Alice: Madness Returns - Love the aesthetics and the atmosphere.
Nier (2010) - I'm probably one of the very few people who enjoyed the original game much more than Automata.
And of course, the obligatory Soulsborne series, 2d anime fighters (melty blood, guilty gear, blazblue, uniel etc), and probably a few more games that I can't think of right now.