I believe The Beatles: Rock Band came the closest to being perfect. Eveything about that game was just beautifully done and the only things missing was Pro Drums, an option for Keys, and a few more Beatle songs (Hey Jude, Strawberry Fields Forever, Yesterday etc. etc.)
Outer Wilds. I consider it the best video game ever made and I’ve spent quite some time thinking about if there’s something I could add, change or remove that would improve it and so far I’ve yet to come up with anything of substance (beyond tiny QoL changes or reeeally nitpicky stuff).