It's all about old school rap man. Mafioso rap, g-funk, even OG gangsta rap.
Here's my list of top 20, my list is classified under flow/lyrics that make sense:
1. Tupac
2. Eminem
3. Dr. Dre
4. Raekwon
5. Bizzy Bone
6. Notorious B.I.G.
7. Papoose
8. Ghostface Killah
9. Snoop Dogg
10. Warren G
11. The Game
12. Nas
13. Big L
14. B-Real
15. Rev. Run
16. Ice-T
17. LL Cool J
18. GangStarr
19. Eazy-E
20. Only exception - Common
I basically listen to their music because of their flow. I admire how rappers spit, not what they spit.