I believe it’s “sensei…”
Sorry, don’t mean to nitpick, and if it’s just a brain fart I’m doubly sorry. I just know I like to have the lyrics corrected for me if I’m not understanding something, so I can look at them and say “Ohhh, is that what they’re saying?!”
Method Man, who is from Wu Tang.
Listen to the tune Shadowboxing, for instance, off Liquid Swords by Genius/GZA.
It doesn’t translate great, but he incorporates rhyme, and flow, and word choice beautfiully.
link to lyrics.
Did I mention Weird Al? Yeah. Weird Al.
The OP mentioned Ludacris and I agree I think he’s got some fantastic wordplay.
I also like the Beasties … but the newer Beasties. Not “I did her like this/I did her like that/I did her with a Wiffle ball bat” but stuff like:
“Dogs love me cuz I’m crazy sniffable”
“I don’t like to fight, I don’t carry a piece/ I’m permanent pressed so I’m always creased”
“Like Ma Bell, I got the ill communication”
“If my rap’s soup my beats is stock/step from the tables as I start to chop/I’m the lumberjack DJ Adrock”
They make me giddy with their rhymes.
It’s all about the Pentiums, baby. 
ODB deserves honorable mention, if only for "rappenin’ is what’s happenin’. " 
Wu Tang is for the children!
I’m always quoting this one with my brother:
If you try to knock me you’ll get rocked/I’ll stir fry you in my wok/Your knees’ll start shaking and your fingers pop/Like a pinch on the neck from Mr. Spock."
Of people not mentioned… Nas, Cannibal Ox, Jedi Mind Tricks, and Serius Jones.
And it’s all in the delivery, you know? The way they hit the words ‘rocked’ ‘wok’ and ‘Spock’. Love that quote.
Also, Trunk, that link you posted is impossible to read without feeling Meth’s amazing delivery. He has a style that really drives the lyrics home. Love that Gza album.
Flander, how you can mention Iron, and not mention that Math is way better is puzzling to me. But Iron is nice too.
I agree with those that mentioned Eminem. He has some pretty clever stuff. His group D12 has surprisingly witty lyrics, but I am not a big fan of them.
I love this freakin’ thread so much! Thank you Naja for starting it! I am going to find some MC Frontalot for my MP3! I never heard of him before, but those lyrics are nice. I can’t wait to see how he delivers it. Thanks to Phase42 for pulling my coat to him.
Came in here to recommend Mos Def, but you’re already a fan. You might also like Jurassic 5 and the Swollen Members, though I’ll admit I probably wouldn’t pay attention to their lyrics if their beats weren’t so good.
Please remember to post only small samples of lyrics (usually a quick stanza) so as to avoid copyright violations. You can then link to the remaining lyrics.
I’ve gone through and edited some of the longer lyrics postings, and have, undoubtedly, butchered them. Sorry about that, but please be sure to re-read the forum rules on copyrights before posting lyrics.
MATH is a good rapper, I think Iron’s lyrics are WAY better. He has lots of double meanings in his battle with MATH. In fact, I think the entire first round is brilliant on Iron’s part. But to each his own.
[hijack]
Anyone who might be interested in battles, check out Jumpoff.tv for their yearly World Rap Championships. This year’s competition was pretty hilarious. There are a lot of bad teams, but the stars shine bright. Check it out.
[/hijack]
Some good suggestions so far. I can’t believe it took so long for someone to mention Nas… for shame!
Some other clever wordsmiths:
Blackalicious (aka Gift of Gab): his command of language is insane. I can’t help but be impressed every time I hear Alphabet Aerobics.
J-Live: not unexpected, considering he started off as an English teacher before he was signed.
Styles of Beyond: some misses mixed in with the hits, but when they’re on, they’re ON.
Yeeeeeeeeesh. I posted like, the fourth verse of the song, and you cut that down into nonsense! Skip, I understand that you probably don’t keep up with that brown sound, but duuuuuuuuuuuuuuuuuuuuuuuuuuude, come on. Rappers fit a LOT more lyrics into one verse than rockers fit into an entire song. What may look like a huge chunk to you is probably one verse.
Big L, rest in peace. 
Lifestyles is such a classic.
I agree. I think he’s brilliant when it comes to crafting his lyrics.
I’m a big fan of Busdriver.
**Word **
I’m not very knowledgable about rap, but I think POS’s “We don’t wave our hands in the air like we just don’t care anymore, we wave our hands in the air like we just don’t care anymore” was clever
Sorry about that. Typically, quoting a single verse of a song has seemed to be acceptable. For most pop songs this usually amounts to 4-8 lines, but the nature of rap means that a single verse is more … verbose. In the case of the lyrics I posted, despite the actual number of lines it was still a single verse, amounting to only 1/3 of the complete lyrics.
Perhaps this can be specifically addressed in the rules? Because while the concept/thought in a sung song can be demonstrated by quoting a single 4- to 8-line verse (representing 25% - 33% of the song), selectively pulling 4-8 lines from a single verse of a rap tune usually doesn’t get the point across at all, as those lines may represent less than 10% of the song.