As a basshead, my winner is the Focal Stellia ( for now..)
such a dynamic headphone, the bass hits are really physical, its crazy!! i doubt i will let this one go honestly.
i tried the meze99, trx-00 maho, lcd-x, zmf atticus, zmf auteur(+classic), hp-3 and many more ( altough, the other ones are less bass oriented ). the only one that really impressed me in those is the Atticus but it was missing some air and speed to me. the focal stellia has the fastest, most strongest bass ive heard. High quality bass, tight and controled... im in love! so much definition and details as well without being harsh .