Classic Goat

Strictly Business (grown on me a lot lately)
Unfinished Business (grown on me a lot lately)
Business As Usual
Back In Business
Out Of Business

If you include solo albums, then that adds PMD - Business Is Business. The Hit Squad is also one of the best crews ever in hip hop. And IMO they are the only group to have the best album of the year 3 years in a row (88, 89, 90). And Erick Sermon is a great producer and both Sermon and PMD are top notch rappers and pioneers of the rap game. I don't understand, why are they not in the GOAT conversation. IMO it goes.

M.O.P.
EPMD
Gangstarr

But that's just me, what do you think about this issue?
I gotta go to class, but I'll just add this. I rank groups based on how good they're discography is, not just how good individually they are at rapping. Also lyricism is only one factor that determines a good rapper. Sermon and PMD excel in all other areas.