If you mean just Bay/Central Cali artists, these are songs that, when I first heard them on their respective artists' CDs, were "clinchers" for me in knowing there was something special about them as rappers and the production choices they made:
Short But Funky--TOO SHORT
Let's Get A Telly--MAC MALL
Return Of Da Baby Killa--BROTHA LYNCH HUNG
The Weekend--N2DEEP (yeah, I know, "Back To The Hotel" was first, but hey...)
Mr. Millimeter--JT THE BIGGA FIGGA
UndaTheColdWorldInfluenceOf11/5--11/5, THE COLD WORLD HUSTLERS and U.D.I.
Part of Survival--RBL POSSE
The Shit That Will Fuck With Your Brain--THE CLICK
Rat Heads--E-40 (as a solo artist)
The Hemp Museum (title track from CD)--B-LEGIT
Whatcha Like--MAC DRE
The Autopsy--C-BO
PEACE!