Em has one dud album, which everyone knows is Encore. Other than that one, if you line up SSLP, MMLP,Eminem Show, (about 4 tracks from Encore), Relapse and Recovery, inlcuding his collabs, production, Devils Night, and 8mile soundtrack...it is hard to argue with Em's body of work. Nas is who I believe is goat, but like somebody already said, its more about who is in the discussion of goat. Eventhough i like Nas' catalog more, Shady has to be in that discussion. If he's not, then what you and I listen for while we got the headphones on ain't the same I guess.
I guess its still cool to call an Eminem fan a stan. I dont know. That must mean that Jay Z, Nas, Game, Dre, Royce, Tech 9, Lil Wayne, Rakim, Xzibit, Redman, Busta, 50, Banks, Dj Khaled, Alchemist, Premiere, B.O.B., Nicki Minaj, Fabulous, T.I., Rick Ross....etc it goes on and on, are all "stans" as well. They have all done interviews saying Eminem is in their top 5, or that he's one of the greatest.
The best way to find out who really is the best at what they do, whether its football, basketball or hip hop, is to ask their peers. How many interviews have we seen with defensive lineman and linebackers talking about trying to tackle Barry Sanders, or someone trying to gaurd Jordan? Feel me?