For me, it’s one of two choices:
Final Fantasy VIII - It’s one of my favourite entries in the series and think they’ve ignored it far too much over the years. There’s a lot they could do with it, not just visually, but with the story and mechanics too.
Final Fantasy Tactics - This game is just fantastic all round, and I can’t say any more than that.
What would you choose?
If it was Squaresoft. Everything from I - XXIII. Square Enix? Meh, give them ii, iii, viii, and TT because its fun no matter what. Hell, give them a shot at FFI and see if square Enix can redeem themselves and recreate the whole series.
And FFI has already been made convoluted by Dissidia, so maybe they’d be less tempted to add further timespace fuckery. I’d be down to see if they could present the original story in a way that isn’t a NES game (has a story beside the opening and ending cutscenes).