I'm definitely a fan of the entire series. It's the sense of wonder I get from playing the games that so far other series just haven't matched consistently. There might be some exceptions to that, but they generally aren't very long series, and/or are a continuous story. A good example of this would be that I loved the first Wild Arms game, but didn't get pulled into the next one. I loved Grandia, but not as much as FF games. I love Elder Scrolls, but not consistently (Like Morrowind and Skyrim a lot, the rest aren't as special). I love Subnautica and it has the sense of wonder for sure, but it's short and in a persistent world.

Final Fantasy is relatively unique in it's ability to consistently create brand new worlds that capture me every time.