40. Eminem on 50 Cent's "Patiently Waiting" (2003)
Album: Get Rich or Die Tryin'
Label: Aftermath, Shady, Interscope
Eminem manages to cover all the bases in this dominating guest spot from Get Rich Or Die Tryin'. He brags about his Shady Records power moves ("Y'all know what time it is as soon as 50 signs on this dot"), compares himself to rap legends ("Take some Big and some Pac and you mix them up in a pot/Sprinkle a little Big L on top, what the fuck do you got?"), and throws in a typically tasteless finisher ("Shady Records was eighty seconds away from the towers/Some cowards fucked with the wrong building, they meant to hit ours").
The only problem is that Em rocked his verse so hard that it makes 50 sound almost amateurish by comparison.