>>6442502FF4 and 5 for basic and classic themes/gameplay but with quality of life and storytelling people talk about
6 for the sweet spot between the classics and the 7 era and honestly one of my most favorite FFs
9 for comfy and similar to 6 but also massive feels
10 I have a love-hate relationship with
11 and 14 are MMOs so they're optional but insert free trial copypasta here
12 only play if you get the zodiac age version
13 and 15 are Square's pathetic attempts to chase their next FF7 and they failed miserably and they should be treated as such failures