What I look for in a rapper is his ability to address social issues and play with words. So much of the beginning of hip-hop was explaining the injustices and pain of the culture the from which the music is born. That is just lost in modern rap. It's all about sex, drugs, partying and materialism and does not provoke thought. It's actually pretty sad.

My favorites:

For pure lyric mastery (both the words and how he says them), I don't anyone much better than Talib Kweli. The first stanza of the following just blows my mind

Talib Kweli - For Women
http://www.youtube.com/watch?v=0qkjtK3O15Q

That song has an actual story to it and addresses social issues, both of which are missing from all genre of music, nowadays.

Also, Mos Def could lay down some amazing and thought provoking tracks. He and Talib Kweli were Blackstar, which was completely badass.

Blackstar - Respiration
http://www.youtube.com/watch?v=eeTnog5RRQo

The poetry of that song is just amazing: extended metaphor, personification, symbolism. I teach this song during my poetry unit.

Lastly, gotta give my love to Tupac. Some of his shit is so dope, I can't even explain it.

Im a big Mos def fan myself.

Lyrically hes untouchable imo. Also, Lupe Fiasco gets an honorable mention imo.
for lulzy effect tho this video had me on my ass for like 3 days.

http://www.youtube.com/watch?v=El1mZpv-V4o

Oh, I forgot in my attempt to post all that deep shit to add something that freakin rocks just because it's hilarious and fun.

I guess this is considered rap...but I could listen to Cee Lo's "Fuck You" all day long. The music is so awesome and some of the lines (especially the back up singers) just have me rollin'.

http://www.youtube.com/watch?v=pc0mxOXbWIU

I picture the fool that falls in love with you
(oh shit she's a gold digger)
Well
(just thought you should know *****)
Ooooooh
I've got some news for you
i really hate yo ass right now

KRS1 and Mos Def are more about lyrical content than flipping words and complex structure. KRS1 *started* a lot of things, but has been surpassed in each technique by many artists. Mos Def isn't really that great of a lyricist, more of a content guy, same with Tupac.. Talib Kweli shouldn't even be in this conversation. Cee Lo is just fucking gangster.

I'm a personal fan of Royce.

http://www.youtube.com/watch?v=KkzxW...eature=related

Being a metalhead, I am very, very picky about hip hop artists I listen to.

Some local bay stuff I've been on for a mintute too

The Grouch
Tooshort
Mac dre(not thizzle bs)
E40
B-legit
Del the funky homosapien

Also other stuff like:
Slug/felt/atmosphere
Sage Francis
MUrs

best rapper in the world?

http://www.youtube.com/watch?v=Z9lg6HqJeY0

Biggie by far for me. Tupac a second, Dr. dre probably a third. I care more about the finished product than if someone can write poetry.

I think a lot of chamillionaire's mixtape messiah series is pretty amazing too.

http://www.youtube.com/watch?v=tpbmQRg4PkA