For me, Witcher 3 is the best game of all time. It's hard to explain how when it came out, it just made every other RPG made around the same time feel like it was from a previous generation. Graphics, characters, game and quest design, dialogue, story, everything was on a level that hadn't been seen before. In many ways, RPGs are still playing catch up. I think Dragon Age Inquisition won GotY the year before the Witcher 3, and it felt like a game 10 years older.
Funny enough, I feel like Clair Obscur is in many ways similar thematically to what I consider was the Witcher's storytelling high point, a quest from the first expansion (Hearts of Stone).