Can't limit it to under 20 just yet. I still need more time with all of these but as of right now in no order:
Roc Marci x Alchemist - Elephant Mans Bones
Big Cheeko - Block Barry White
Westside Gunn - Peace Fly God
Benny - Tana Talk 4
Al Divino x Big Ghost LTD - 2 Nights in Marrakesh(counting it as this year for my own reasons, sue me lol)
Rigz x Muggs - Gold
Earl Sweatshirt - SICK!
Conway - God Don't Make Mistakes
Black Thought x Danger Mouse - Cheat Codes
Mach-Hommy - Dump Gawd: Triz Nate (4 Part Series)
Alchemist x Curren$y - Continuance
Lupe Fiasco - Drill Music in Zion
Pusha - It's Almost Dry
Billy Woods x Preservation - Athieopes
Elucid - I Told Bessie
Armand Hammer - WHT LBL
Black Star - No Fear of Time
Boldy James x Real Bad Man - Killing Nothing
Your Old Droog - YOD Wave
Droog x Fahim - Wolf on Wall Street Vol. 1 & 2
Domo Genesis - Intros, Outros, and Interludes
I also haven't listened to this new Larry June yet and I'm sure he'll be a contender for my list as well.