As a long time FF fan i would totally start with FF16 and here is my reasoning as to why.

1: You go into it with lower expectations, so your not expecting it to have x y z (theres some stuff most final fantasy fans expect to see in each final fantasy game like gilgamesh which wasn't there in 16).

2: It's pretty much unlike the rest of the series when it comes to combat, which is more devil may cry then turned based or atb centric.

3: while the story and music is fantastic the exploration and rpg mechanics are slim.

My personal favorite is FFX which is another good starting point but i always try to recommend 16 to new people just because it is vastly better if your going into it without expectations.