Absolutely, Chagaev. Has faced a murderous puncher in Virchis and some other decent opposition and never been visibly hurt.
Wlad does. Non of the other heavies have been hit by power hitters like Corrie Sanders, Lamon Brewster and Sam Peter. Wlad took their best shots and kept getting up. No one can KTFO of Wlad in the heavyweight division right now.
Maskaev has the worst chin. Everytime he's lost, it's been by KO/TKO. Edit: Wlad and him are tied I guess, because the same above can be said for Wladdy boy.