Cash Cow Franchise: While they certainly have many other IPs that are popular and profitable, this is the video game franchise that turned Square into a powerhouse publisher and made them kings of the JRPG genre alongside Enix, at least until the two companies merged and became Square-Enix.
Dueling Games: Before Square and Enix merged, Final Fantasy and Dragon Quest were very much rivals of one another. Even today (mainly in Japan), there is still some rivalry over which series is better.
And within the Broken Base of Final Fantasy fandom, while many different games' fans are at each other's throats, likely the best-known rivalry is between fans of Final Fantasy VII and its direct predecessor Final Fantasy VI, with many of the latter resenting the former's popularity, which is believed to be undeserved as compared to their own game, and the former thinking (if they care at all) that the title of best FF game is theirs and the old-school fans need to get over themselves already. This usually manifests itself as fighting over which game had the coolestvillain.
Panzer Dragoon Saga was made to go up against VII and be the Killer App RPG for the Sega Saturn. Unfortunately, Saga was released late into the Saturn's life, so it never stood a chance.
Magnum Opus Dissonance: Hironobu Sakaguchi considers IX the best title in the series. The game received mixed reactions and sold the least copies of all the PlayStation installments of the franchise. However, it has since became vindicated by fans and is the highest-rated PS1 entry of the franchise on Metacritic, so perhaps time showed Sakaguchi to be right.
Meaningful Name: A lot of the names in the FF world draw upon mythology, religious beliefs, and fiction. A good example is all of the summons, who are named after mythical figures, places, or objects such as Leviathan, Kujata, Shiva, Hades, and Ark to name a few.
Some of the weapons are named after legendary ones such as Excalibur, Masamune, Gigas, and so forth.