This is a REALLY close race because they're all beyond great games.
Persona 5 will last you the longest easily, but you have to be really in the mood for what it is going for. The gameplay isn't as gripping as the other two games you listed, but the atmosphere, story, and characters are the go to, it's a fantastic ride if you want a really polished and well told anime story. Plus it is over 100 hours while the other two are around 20-40 so you get more time out of it if that's a consideration.
Horizon is my favorite of the three, it has a fantastic world and the gameplay is so well thought out for what I thought would be a relatively generic open world title. It still has rudimentary stuff like collectibles, climbing towers, etc. like all open world games. But preparing for and fighting all the different machine types really feels akin to something like Monster Hunter sometimes, it's quite incredible. Gorgeous too.
Nier Automata is incredibly unique, has plenty of elements in it that you'll only find in a Yoko Taro title, and has that Platinum games polish I love. But I do think it's story falls a bit flat at points (many people seem to disagree with me though), and the gameplay isn't quite as deep as it seems like it might be at first. It strikes the balance between great gameplay and story but doesn't quite "master" either I feel. The end of the game is incredibly strong though and it has a ton of very interesting deeper meta commentary and philosophy.
Personally I'd go
Horizon > Persona 5 > Nier Automata
But this is still a really close race. Depending on my mood the list could easily change.