A famous white MC who is notorious for his offensive lyrics and vulgarity.
He's probably the most technically skilled MC of all time. His mult-syllabic rhymes, internal rhyming, and vocabulary is superior to nearly everyone in the game, despite the fact that most Hip Hop heads will try to tell you that underground MC's own him (they wouldn't). They obviously haven't heard the "Infinite" album, which is likely the best album I've heard from ANY MC.
The tracks on "Infinite" are perfect examples of why Eminem is the most skilled MC of all time.
One of his best songs is "Infinite" (first track on the album), and for this example I'll be discussing the second verse.
Notice how he is able to weave a particular vowel sound throughout an entire line (example: "One thought in my cerebral is deeper than a jeep full of people"), and how he can make so many words rhyme (example: "I spoil loyal fans/ I foil plans and leave fluids leaking like oil pans/ My coiled hands/"), rather than just making sure the words and the end of the line rhyme, like most MC's do.
Another example of his lyrical talent is from "Tonight", also on Infinite:
"We travel in packs and ravel in facts and gravel in cracks
To find babbling Max, gaffling tracks
I grapple an axe for them baffling acts
The mysterious stab in the backs who dabble in wax"
He starts off with "we travel in packs" and then makes nearly everything else he says rhyme with that (grapple an axe, stab in the backs, ravel in facts, etc).
Keep in mind that I could give you hundreds of genius lines from him, but I only get to use 1500 characters.
Eminem is top 5 of all time.
Some great songs from him: Infinite, Tonight, 313, Biterphobia, Open Mic, Jealousy Woes II, It's Ok, Role Model, Rock Bottom, Microphone freestyle, Rhymin Wordz freestyle, etc.