Enough serious sales talk.
Final Fantasy is a massive flagship franchise for Square Enix worldwide, and we've got FFXV on the horizon. Fifteen!

I've been wondering, whether or not anyone cares, if/when the number ever gets too high. Would it feel weird to you to be saying, buying, or marketing "Final Fantasy 19" or "Final Fantasy 23"? Square has stuck strong with the numeric approach for their titles, and I don't think the franchise will kick the bucket in the near future, so I think it would probably reach the "stupidly high number of sequels" zone before any other franchise. Will they ever need to change the convention or do you not care?

So what do you think? Will our children ever get to play Final Fantasy XXX?

No, I would be very surprise if FFXXX release some day

New Final Fantasy

I dunno, Bravely Default is supposedly a spiritual successor as its japanese subtitle, 'flying fairy', possesses that eponymous FF branding.

Oh you're a vile one, Mr. Grinch.

The "FF" in the subtitle is actually a misdirection. If you have no intention of playing it (assuming you haven't), I can explain why in a PM if you'd like. But the gist of it is that I don't think future games in the series will share the FF subtitle, and I doubt Bravely Default is going to become the new Final Fantasy or anything like that.

As for the future of the Final Fantasy series, anything can happen to a big company like Square Enix over the span of several decades. But I believe that if my children live long and healthy lives and are very lucky, they may witness the release of Final Fantasy XV.

Fap Fantasy? Please? Although, LR is kinda like that with all dem cosplays

I don't see them moving away from the numbered releases, no matter how high the number gets.  As long as they keep selling they are gonna keep coming out. 

I don't see the series adopting a new naming convention at this point. It's been 27 years and fifteen games, it's hard to imagine it changing now. Of course they could always add some subtitle and reset the number. Who knows.

They should go the Hollywood route and just call the next game "Final Fantasy"