if you saw the Quik and Breed threads ill try to help you with the others...
Compton's Most Wanted - Ive only heard "Its a Compton Thang" in full but id recommend it. Ive heard parts of Music to Driveby and id definitely recommend it from what ive heard. Honestly ive heard good things about their first 3 albums so just start there.
MC Eiht - part of CMW, get his debut album "We Come Strapped" essential listening
Kool Keith - one of the best rappers and creative artists of all time IMO. You need a lot of his material. I'd get his work with Ultramagnetic MC's. Get "Critical Beatdown" and "The Four Horsemen".
In terms of Keith's solo projects get the following, and id probably get them in this order:
Dr. Octagon - Dr. Octagonecologyst
Kool Keith aka Dr. Dooom - First Come, First Served
Kool Keith - Sex Styles
Masters of Illusion (with Kutmasta Kurt and Motion Man)
Project Polaroid (with TOMC3)
Ultra (Kool Keith and Tim Dog) - Big Time - this album is almost never talked about but it goes hard as fuck, highly recommended
Dr. Dooom 2
After those, if you like Keith a lot id get Diesel Truckers, Spankmaster, and Black Elvis/Lost in Space.
I haven't heard Analog Brothers (with Ice-T) or The Cenobites album but ive heard good things and will eventually get around to them
K-Rino ive liked everything ive heard from him...which is Danger Zone, Stores From the Black Book, Solitary Confinement, Blood Doctrine, Annihilatrion of the Evil Machine, and Book Number 7
people always say good things about Time Traveler too
Show & AG - Runaway Slave is one of the best albums ever and Goodfellas is a ner classic follow up some people even like it more. Get those 2 first then if you like them get Full Scale and Live Hard
UGK - start with their first three...Too Hard to Swallow, Super Tight, and Ridin Dirty, Ridin Dirty being my favorite. Then get the rest
Too Short - start w/ these:
Life is Too Short
Shorty the Pimp
Short Dogs in the House
Get in Where You Fit In
id recommend all, but his only other album ive heard is Blow the Whistle which is pretty good
Xzibit - Get his first 3 asap
8ball and MJG - get On Top of the World, In Our Lifetime Vol. 1, and Comin Out Hard in that order IMO