Because the games aren't linked through storyline maybe picking by choosing a setting you like would be a good place to start.
VII is futuristic with steam punk vibe
VIII is futuristic
IX is medieval style (also Steiner is just a lovable idiot
)
XIII is also futuristic but as most people have mentioned here, best probably to start with the most noteworthy 3
VII is futuristic with steam punk vibe
VIII is futuristic
IX is medieval style (also Steiner is just a lovable idiot

XIII is also futuristic but as most people have mentioned here, best probably to start with the most noteworthy 3