If there's a Millennium Prize problem race, I'm most excited for P=NP and the Yang-Mills existence and mass gap solutions. Knocking those off feels more world-changing.

Probably, P vs NP would be the last one to be solved, said by Terrence Tao in 2009.

source: https://www.youtube.com/watch?v=PtsrAw1LR3E&t=2727s