For the most part you guys have metioned some good albums. But if you want to catch up to the new classics, cop the following

Game - The Documentary

T.I. - Urban Legend

Kanye West - Late Registration

Juelz Santana - What the Game's Been Missing

also from a few years ago

Jay Z - The Black Album

Nas - Stillmatic

Jim Jones - On My Way to Church

Any of 50 Cent's old mixtapes (G Unit used to be straight fire)

Young Buck - Straight Outta Cashville

Styles P - A Gangsta and a Gentleman

Eminem - The Eminem Show

All of these are worth picking up. I'm surprised no one mentioned Jay