I only listen to old school rap because the new shit sucks imo.

Tupac - Hit 'Em Up, Dear Mama, I Get Around, etc.
Bone Thugs - Mo' Murda, Notorious Thugs, East 1999, For the Love of Money, etc.
Eazy-E - Boyz in the Hood, Easy Duz it, Easier Said Than Done, etc.
Gangsta Pat - I Wanna Smoke. Killa, Deadly Ass Verses, etc.
Alot of stuff by NWA