FF2 is easily the worst. I am saying this as someone who really likes FF1, and I like retro games in general (if they are good). FF2 is just a plain terrible game. It's leveling system is also very similar to a certain Western RPG that I really hate.
If you only want to count games that made it out of Japan on their original system, then I'd say FF8 is the worst. I actually really liked the characters and story, but the gameplay was just terrible. I mostly just wanted to play the card game, because it was fun, while the main game was a huge chore. Of the FF games that I've actually beaten, it's the only one that I never want to play again.
Haven't played FF14 though (neither O.G or Reborn), and I only played FF15 for an hour and then never came back to it. All of the other games that got a North American release on their original system I've beaten, and most of them are extremely good.
curl-6 bet me that PS5 + X|S sales would reach 56m before year end 2023 and he was right.
My Bet With curl-6
My Threads:
Master Thread, Game of the Year/Decade
Switch Will Be #1 All Time
Zelda Will Outsell Mario (Achieved)
How Much Will MH Rise sell?
My Bet With Metallox