Mobb Deep is one of New York City's most gritty hip-hop crews. It consists of Prodigy and Havoc.
Prodigy and Havoc have been together since the early 90's, releasing their first album while still in high school. One of their early albums was entitled Juvenile Hell, and featured songs such as Peer Pressure, about the travails of being young. Since then, their albums, especially with Hell on Earth, have been very crime oriented.
Although Mobb Deep's music and lyrics is violent and explicit, I personally don't find it to be in a egotistic or braggadocious way, unlike many so-called 'gangsta' rappers. Rather, Mobb Deep has turned nihilism into an aesthetic.