this is almost impossible, because i never have any idea to include things like "taste in beats" as criteria, or whether it's a purely lyrical/technical thing
assuming the former, an unranked top ten is probably the best i can do, so:
posdnous
cee-lo green
jay electronica
biggie
mf doom
mos def
nas
andre 3000
black thought
bun b
--
And if you don't know, now you know.