EPMD.
Their run was actually 4 classics in a row, if we're being honest. What Erick was doing with production from '88-'92 was way ahead of its time. Their first 4 albums are untouchable.
Paid in Full and Follow the Leader were full of classic tracks, but things started to slide around Let The Rhythm Hit 'Em. But with EPMD, they got better album after album. Business as Usual is still their best album, to me. And that's a straight listen, with no skips, even today. The issue with Eric B and Rakim, was that they couldn't get the production to match where Ra was lyrically. So their sh*t got stagnant around the third album, with their best work being on the first two joints.