Rap - Tupac, Notorious B.I.G, Lil' Wayne, Wiz Khalifa

[Andretti]

wiiz kkalifka dis cauool.

[Ad Bot]

[Daffy]

Vinnie:
-snip-

I do enjoy some Vinnie Paz, especially Jedi Mind Tricks http://www.youtube.com/watch?v=7r0KpWMNxnM.
Hilltop Hoods is really good too http://www.youtube.com/watch?v=KpKMXQ5FzL4

[Mr.Interceptor]

Fu Schnickens - Sneakin' Up On Ya

[Messes]

Please add to OP

Gucci Mane
Waka Flocka Flame
Lil Wyte
Three 6 Mafia
Kottonmouth Kings

Good ones, I know I'm missing a few more I really like, but I gotta get to school.

[Aphtonites]

Lil wayne is nothing more than a man who decided to shrink his voicebox.
No real talent involved.

[|Shadow]

Lowkey is awesome.

[Tokerovin]

Another one that belongs on the list along with a link or two is Rhyme Asylum.

Here are some good songs by them:
http://www.youtube.com/watch?v=EzaGj39NEis
http://www.youtube.com/watch?v=g3wttJlNTC8
http://www.youtube.com/watch?v=OyiWyTIbfPM
http://www.youtube.com/watch?v=xh5TxAfwUrA