DJ Premier
Hard To Earn (fuck is Born To Earn son?)
The Sun Rises In The East
Livin’ Proof
Wrath Of The Math
Moment Of Truth
Countless of joints for top tier MCs in the 90s

Pete Rock
Mecca And The Soul Brother
The Main Ingredient
Center Of Attention
Soul Survivor
Petestrumentals
Various artist joints plus remixes...who else can remix a Preemo joint and make it better?

RZA
Enter The 36 Chambers
Tical
Return To The 36 Chamber: The Dirty Version
Only Built 4 Cuban Linz
Liquid Swords (how the fuck did you not mention this in your original post?!!?)
Ironman
Forever

J Dilla
Beats, Rhymes & Life
The Love Movement
Like Water For Chocolate
Fantastic, Vol. 1
Joints for Pharcyde, remixes...and Stakes Is High!

To me...

DJ Premier has the longest catalogue of absolute bangers.

Pete Rock at his best is better than everyone.

RZA has the best run of albums...and not even just from a beat making perspective but from an executive producer perspective

J Dilla is probably the one with the most range and proved to be relentless with his craft on some student became the teacher shit.