My favorite has to be

NWA - 100 Miles and Runnin
Eazy E - Eazy Duz It
The DOC - No One Can do it Better
Eric B and Rakim - Paid in Full
Run DMC - Run DMC

I just can't get away from the WC style as my favorites. Run DMC is there because I just used to love to listen to that. Still do. Eric B and Rakim is just classic. Later, QD.