FF1 - for being the game that saved Squaresoft's ass.
FF7 - for turning Squaresoft into a global powerhouse.

Each of the Final Fantasies before VII were already multimillion sellers. VII was bigger, but it was a matter of degrees. It was only a "cult" following in that most of the people here only heard of it during the PS1 era, which makes sense because most of the people here weren't really gamers before that point.

The same is not true of many - FF7 did not put the series on the map. It made it more popular, but the same thing can be said about X.

Eh...7 was important, sure...but I don't know if I like Square Enix as much as I liked Square back in the SNES days.

But without FF1, there probably would be no Square or Square Enix so, FF1 wins.

the first one obviously

FF1 for copy-pasting DQ and succeeding in Japan

FF3 for introducing the job system

FFIV and FFVI for expanding the story, characters, narration and personality of the characters.

FFVII for being a worldwide success and having the most impact in Japane and worldwide as well.

FFX for its overwhelming cinematography, creating the most emotions to gamers of Titanic (the movie) level.

FFX-2 and FFXII for bringing fresh air to the gameplay and the latter by introducing the ADB system, an big leap from the ATB that was stuck for one whole generation, and making battle transition seamless.

Wasn't Final Fantasy most notable for its departures from Dragon Quest? Or am I losing it?

Neither did I... but to be fair. Without 7 FF would just be Dragon Quest... with slightly more American sales.

The FF1 point does stand though I suppose... in regards to Square. (Enix would be fine... and they might of bought square's property, so Square Enix might exist... just under the name Enix.)

Sorry, I just can't let this slide. SM64 arguably more important than SMB? By what argument exactly? Let's look at this objectively:

1.

- SM64 set a standard for 3D platformers.

- SMB: set the standard for _games_  and took Nintendo from small time arcade developer to worldwide gaming domination, and single-handedly revived the games industry.

2.

- SM64 sales: ~12 million

- SMB sales: 40+ million

 3.

- SM64 did what exactly for gaming culture?

- SMB was the major launch title for the single most known gaming character and icon in the industry, and indeed one of the most known fictional characters in the world.

How many people can whistle any tunes from Mario 64? How many can (and DO) whistle the SMB overworld theme, play it on guitar, piano, cymbals, drums, a Tesla coil (check youtube).

4.

Even my mom played SMB1. End of story. It's probably the most played video/computer game in the world, maybe with the exception of Tetris and Solitaire.

 Do you want me to go on?

The comparison between SM64 and SMB is outrageous. I can only assume you are too young to have grown up in the 80s. Because we who where there, we know what SMB meant.

FFVII is easily the most popular and influential game in the series

FF7 was the most important....as it bumped the franchise up from sales of 3 million to 10 million

I would say FF1 & FF6 were also important

FF12 was important too for its new battle system