Story-related achievement--can't be missed.
Spoilers: The boss battle with Bane occurs in the Medical Facility after you rescue Gordon. His battle is like the Titan battles--batarang his face when he charges and dive out of the way. Do this twice, then run up and punch him a little to remove a vemom tube and repeat twice. After every time you swipe off a tube, joker's henchmen will jump in to battle as you duke it with Bane--take care of them but definitely avoid getting trampled by Bane--he does a fair amount of damage.