I had to vote Eubank, I remember watching Benn Vs Eubank 1 and Eubank took every shot in the book that night and pretty much walked through them. Other fighters tested Eubank's chin but none punched like Benn at middleweight.
Except Eubank wasn't big on clinches unless forced into it. He was hurt, inititated the clinch then convered up for ages afterward. He was hurt, get over it. I also believe he was briefly hurt against Schommer. His chin is not comparable with McCullough's. This isn't even close.
He says Schommer hit very hard, knocked his teeth out and made him see flickers of white lights. Eubank clinched a lot of in the Logan fight, Holmes fight, Calzaghe fight, both Benn fights and second Watson fight.