i did a thread on this in 2010, and illmatic won by a landslide, followed by reasonable doubt and some others:
79 - Illmatic
25 - Reasonable Doubt
23 - The Infamous
21 - 36 Chambers
20 - Only Built 4 Cuban Linx, 7 Day Theory
17 - Ready to Die
16 - Doggystyle
14 - All Eyez On Me
13 - The Chronic, Liquid Swords
12 - Midnight Mauraders, E1999 Eternal
11 - Blueprint, The Score
9 - Death Certificate, Low End Theory
8 - Train of Thought, Black Album, College Dropout
7 - Hell on Earth, Be, Ridin Dirty, Food & Liquor, It Was Written
6 - Life After Death
5 - Return of the Mac, Mos Def & Talib Kweli Are Black Star, Dogg Food, Full Clip: A Decade of Gangstarr, Boy In Da Corner, Diplomatic Immunity, Eminem Show, Southernplayalistic..., We are the Streets, Its Dark and Hell is Hot
4 - Paul's Boutique, Aquemini, Bow Down, The Genie of the Lamp, Doe or Die, Mecca and the Soul Brother, Strictly Business, Miseducation of Lauryn Hill, Raising Hell, Trap Muzik, Stillmatic, ATLiens, Below The Heavens, Fear of A Black Planet, Ill Na Na
3 - Efil4zaggin, Underground Kingz, The Cool, The Cold Vein, Muddy Waters, 400 Degrees, Creepin Ah Come Up, Me Against The World, Capital Punishment, Flesh of My Flesh
2 - Resurrection, Thug Life: Vol 1, Ghetto D, 2000 BC
1 - Stress: The Extinction Agenda, Get Rich or Die Trying, Paid In Full, Street Gospel, The Game is Thick, Part 2, Nocturnal, Lost Tapes, Lets Get Free, Art of War, Game Theory TM101, Supreme Clientele, Fishscale, AmeriKKKa's Most Wanted, NORE