I've republished the top 5. 

As much as I loved KRS-One growing up his later work I think pushes him down the list. Happy to see Kane high on the list. Surprised Eminem was at #13. Other things I disagree with but these things are always entertaining.

5. The Notorious B.I.G. Lacking any real social message, Biggie possessed enough pizzazz to sway audiences young and old. Best Album: Ready to Die

 

4. Nas Some call him a street prophet for his poetic, conversational-style lyrics. An absolute master of lyrical extravaganza, Nas often paints a picture of urban life in his rhymes. Best Album: Illmatic

 

3. Big Daddy Kane The King of Swagger, Kane dazzled the rap world with his peculiar flair and flamboyant wardrobe. Countless others (including Jay-Z, Biggie, and Snoop) would later adopt his player persona. Best Album: Long Live the Kane

 

2. KRS-One The Teacha transformed the violent brusque of ghetto life into a story of uplift and self-awareness, starting with BDP's incendiary debut, Criminal Minded. Best Album: By All Means Necessary (w/ Boogie Down Productions)

 

1. Rakim While others bragged about their guns, Rakim celebrated his swagger. A smooth, laid-back flow, intense lyricism, and positivity were his stately hallmarks. Best Album: Paid in Full (Eric B. & Rakim)

http://rap.about.com/od/toppicks/ss/Top50Emcees.htm

my list would be a bit different, but it's certainly not like blender-level embarrassing or anything.

although dmx would definitely be missing my top 50. or 200.

El-P should definitely be on the list in lieu of DMX.

My Top 20 MCs (a cross b/w impact & favoritism):

20. Big Daddy Kane

19. GZA/Ghostface/Raekwon

18. Ice Cube

17. LL Cool J

16. B-I-G

15. Jay-Z

14. Q-Tip

13. Eminem

12. Slick Rick

11. Big Boi & Andre 3000

10. Doom

9. WC

8. Eiht

7. Vakill

6. Kool Keith

5. G Rap

4. Common

3. Rakim

2. Nas

1. Scarface