Best Eminem guest verse ever is not listed. I believe it is one of his best verses, guest or not. 50 cent- patiently waiting:

If ya patiently waitin to make it through all the hatin
Debatin whether or not you can even weather the storm
Unless you lay on the table they operatin to save you
It's like an angel came to you sent from the heavens above

They think they crazy but they ain't crazy, let's face it
Shit basically they just playin sick
They ain't shit, they ain't sayin shit, spray em' fifty
A to the K get in the way I'll bring Dre and them wit me
And turn this day into fuckin mayhem, you stayin wit me?
Don't let me lose you, I'm not tryna confuse you
When I let loose wit this uzi and just shoot through your Isuzu
You get the messege? Am I gettin through to you?
You know what's comin, you motherfuckers don't even know, do you?
Take some Big and some Pac and you mix em' up in a pot
Sprinkle a little Big L on top, what the fuck do you got?
You got the realest and illest killas tied up in a knot
The juggernauts of this rap shit, like it or not
It's like a fight to the top just to see who'd die for the spot
You put ya life in this, nothin like survivin a shot
Y'all know what time it is, soon as fifty signs on this dot
Shit what you know about death threats, cause I get a lot
Shady Records was eighty seconds away from the towers
Them cowards fucked wit the wrong building, they meant to hit ours
Better evacuate all children, its nuclear showers
There's nothin spookier
Ya now about to witness the power of fuckin fifty