I voted Favors, but I really like the promise of both Burks and Hayward.
It won't be popular, but I'm just not sure yet on Kanter. I see his
best case scenario is as a Charles Oakley type career. He will have a long career and be a solid contributor, but I'm not sure he'll ever be more than a 10 point 8-10 rebound physical player. That is very solid, but not a star. However, I see star potential in all three others.
Edited to add a link to Charles Oakley's career stats -
https://www.basketball-reference.com/players/o/oaklech01.html