Eminem is one most of you haven't mentioned.
i'm surprised at that, because he's a lot better than most hip-hop/rap artists.
His best albums are Slim Shady LP and Marshall Mathers LP.
but if you like those, you have to buy more.
Bliss N Eso is an Australian rapper that kicks ass.
see his song Zion Bash.
if you like things a little more colorful than NaS you'll be impressed.
And i have listened to NaS, I got his "Greatest hits" and honestly it had a bit of a colorblind feel.
Fatboy slim is a hip-hop artist with a rap-like feel, even though it's not always rap in certain songs. Listen to Gangster Tripping and you might like it.
Even though that song consists of only 2 repeating verses/lines (lol) it's nice.
and Rage Against the Machine is a metal/rap band that kicks ass like hell.