Eminem's greatest song is Infinite. That whole album is purer and rawer then any other album he's ever released. If you don't believe me, look it up on youtube.
It truly depends on my mood. Stan is really dark so I can't listen to that when I am in a good mood. To keep my post short, out of his newer songs I like No love and love the way you lie. I love most of his older ones so I can't really specify on that. My least favorite would be most of the songs in Relapse. Not his best in my opinion.
"Best Eminem song" is like saying "Favourite time I got stabbed."
What was that one from the early 90s? The one about...doing something or another? Same time as the one about standing up, but not that song. Meh, I dunno anymore.