Like others have said, there’s no reason to play in order, but to be more specific:

• If you ask someone what their favourite FF is, 90% of people will answer something between 6 and 10, so you should probably start with one in that range.

• 1 is probably not worth playing at all, it hardly even has a story and is very simple.

• 2 is a bit better, but I would say 3 is where it starts to get good.

• 4 and 5 are also very liked and popular.

• 12 doesn’t have the best story, but it’s good, and it has a lot of people’s favourite combat system.

• 13 isn’t bad, but a lot of people didn’t enjoy it. I hardly hear people talk about it nowadays, but maybe that’s just me.

• 15 is probably more liked than 13 but it also gets a lot of criticism. It’s quite modern, though, so it’s probably one of the easiest to get into for most people.

• 11 and 14 are MMOs. If you like MMOs, you should probably choose 14 because 11 is quite old and doesn’t have a lot of players.