I’d actually recommend AC1, so long as you’re down to focus on the dialogue and don’t mind a relatively repetitive (but highly polished) gameplay loop.

It’s definitely the most philosophical game in the franchise and personally that makes it the most interesting, even if the philosophy present is relatively simple. But yeah that’s a solid backlog

I was going to say Assassin’s Creed Valhalla until I saw that the question ends with “because it’s the perfect game”

Valhalla is a deeply flawed game that I honestly sort of hated in that first year but I just keep finding myself playing it again every once in a while. Partly because the game is so goddamned long and my original save file got corrupted so I technically have never even finished the game once, but there’s honestly some really good components hidden in the bloat and poor decision making that bog the game down. Sort of like the Amazing Spider-Man 2