Good question, i am sat here trying to work it out,, LL cool J was good and melle mel was but what about Run Dmc, Ice cube and Busta, then Missy Elliot would have to go into another catagory. Then there is Rob base and 2 pac, oh i don't know,,, not bloody John Barnes thats for sure.
i dont rate 2pac- think he was rubbish,
notorious big was good though.
although im sure they are doing a rap battle together somewhere and sadly yet another "lost" song will be found and released into mainstream- yuk.
If you want a rapper with rhythm, intonation and excellent wordplay check out either Chali 2na of Jurassic 5 or Del tha Funkee Homosapien.
What's strange is that not many people have even heard of them whilst the most famous rappers are those with well produced tracks but lack any actual decent rapping.
If you haven't heard of them, i strongly advise you all to check them out.