I'll just mention the rappers I like best:
Guru/Gang Starr (Love Guru's Jazzmatazz cd's, especially the first one)
LL Cool J (his later stuff isn't very good but I still listen to Bigger And Deffer/Walking With A Panther/Mama Said Knock You Out...)
Q-Tip/A Tribe Called Quest (Vivrant Thing is the tune I wake up to every morning)
De La Soul
Missy Elliott
Never been a fan of Eminem though....