Relapse is insane in the lyrical complexity department but look at it this way; In Relapse, you'll hear Eminem pulling random words out of his head and putting 'em into a sentence and making them rhyme and work at the same time because, with his subject matter, he could say whatever he wanted about anything, it didn't matter if he exaggerated.
And more importantly, and i've said this before, that accent is like a cheat when it comes to rhyming. He can bend words and have hundreds more options that he would have otherwise.
So I would not put Relapse up there with MMLP/SSLP or TES as far as rhyming with purpose using words that fit that you wouldn't normally think of. I say MMLP/SSLP have the best rhyming when it comes to stuff in the back of your mind that you have to rewind and think about, but TES whenever you take into account every other aspect.