Same Song and Dance -
You ain't never gonna break that glass the windshields too strong for you
That line turns the song into something completely different to what the average listener thinks they are hearing, its amazing.
My Fault -
Gogo Gadget Dick
A personal favorite line as it hooked me into the comedy Eminem can bring to his songs

Also the beat in that songs is fucking epic in a proper system.
As for worse? I'm not sure but some songs annoy me that they are great but I have to fill in the blanks myself. Particularly I'm Back and Marshal Mathers.
Also a side note, I hate the skit in Relapse where Eminem throws the disks on the table and the guy goes "Whats this? TWO CD's?". I just hate the way he says two so much, I don't know why lol.