#1 A time limit match with Nakamura winning if it's a draw
The only reason why this one makes the top of the list is due to Nakamura having a wealth of experience in it. In NJPW, it is common for matches to end in a draw. This would be the ideal psychology with which Nakamura could capture the title. On top of it, it is the only possible way in which Styles can come out as a winner despite losing the belt.
If WWE wants this storyline to be progressed further, it would be better if it's a variation of the traditional one-on-one match. While they can perform well in hardcore matches, sometimes a simple one-on-one match does the trick.
Moreover, the NXT Takeover: Philadelphia main event was a traditional one-on-one match with the winner going home with the title. Still, it earned a 5-star rating from Dave Meltzer. Styles and Nakamura are way better performers than both of them. It is high time the kids in NXT know who the real boss is.