He's incredibly over-hyped by some, but I love eminem's rhyme structures and wordplay.

Examples:

Under the influence:

I'm like a mummy at night, fightin with bright lightning

Frightened with five little white Vicadin pills bitin 'em.....

Grab a knife at the blade and stab you with the fuckin handle

So when you find yourself wrapped up in the blinds, hurtin

[Swifty] Bitch it's too late

[Eminem] Cause once you're hung from the drapes, it's curtains

Low Down Dirty:

I lace tunes, I'm out this world like Space Moons

With a bunch crazed loons dismissin brains like braze wounds

Nothing but idiots and misfits, dipshits

Doing whippits, passed out like Sanford snippits

Criminal:

My mother did drugs - hard-liquor, cigarettes, and speed

The baby came out - disfigured, ligaments indeed

It was a seed who would grow up just as crazy as she

Don't dare make fun of that baby cause that baby was me

Admittedly, he has some misogynistic, violent, and homophobic lyrics. He's usually joking, so I don't particularly mind that. I don't know many artists who can have as many rhyme schemes going on at once. The classic example is his "lose yourself". Here's a video which dissects this song.