BASS! BASS! BASS! With some mids. MOAR BASS! Some highs for nice percussion. EVEN MORE BASS!
That’s the best way to describe Hip-Hop music.
Hip Hop as a genre requires a set of headphones with a warm sound, but loads of energy. Bass is what is most important here, but without compromising on the rest of the range. Bass-heavy headphones are something you are looking out for.
You want to enjoy the beats but you definitely don’t want it to overpower the sharp percussions and the bars laid down by the MC. A closed back pair would be preferred, however certain exceptional open back headphones are also great for bass.