Drug Ballad
"I've got no game, and every face looks the same
They've got no name, so I don't need game to play"
"Cause if I get caught cheatin' then I'm stuck with you"
The whole of Drug Ballad is such a great example of Em's writing ability. But more specifically, these are examples of Eminem's unmatched humour.
I could imagine Loius CK having that second example as a punchline after a long set-up.
The Real Slim Shady
"Will Smith don't gotta cuss in his raps to sell his records
Well, I do. So fuck him and fuck you too"
I'd almost go as far and say this is his funniest line. Just perfect.
I have no idea why people try to discredit TRSS.
Cum On Everybody
"Shit I got full-blown AIDS and a sore throat"
Such a brilliant juxtapose. In terms of how insignificant and minor that is when telling someone you have AIDS. But also how significant a sore throat ultimately is.
..and no one seems to like this song.

Kill You
"I said shut up when I'm talking to you, you hear me? Answer me!"
I don't think (I hope not) this is underrated by Eminem fans. Along with the delivery, which makes him sound like he should be in a mental hospital, these lyrics truly show Em's creative genius. This could easily be dialogue for many great movies to do with mental illness' that kids study in English lessons.
Still Don't Give A Fuck
"But if I offended you.. good..
Cause I still don't give a fuck"
Just superb.