Final Fantasy
With such an astounding number of Final Fantasy titles out in the world, TT Games would definitely have its hands full adapting each of those that would make the transition well. The earlier titles, which had a greater focus on the “fantasy” part of Final Fantasy, feel like they would be better choices, since their visual and character designs generally erred on the side of family-friendly. While some LEGO titles have experimented with open-worlds (such as LEGO City Undercover), it might be too monumental a task to recreate the recent Final Fantasy XV with bricks and minifigs.
Nonetheless, turn-based combat and RPG elements aren’t something characteristic of LEGO titles either. So why pick Final Fantasy? The vibrant and colorful worlds that usually serve as the settings for these games would be wonderful to behold as bricks, and come on, who doesn’t want to ride a LEGO Chocobo? Final Fantasy VII might serve as good source material, since it’s fondly remembered, and the game is pretty blocky by default. Also, TT needs to find a way to make “friendship” a gameplay mechanic if they tackle this.