Marshall Matters LP is his greatest, easily. I see no argument for any other album as his #1. Artistically, commercially - MMLP was peak Eminem. The themes and tropes in that album (anger, drugs, misogyny, gay jokes) have permanently characterized his entire name and persona. You think Eminem, you think MMLP.
Yeah I definitely agree with your take on MMLP. It's a fantastic album and defines what Eminem is and all that anger/aggression carries his name in my opinion.
Also yeah if you don't bother to listen Kamikaze and beyond, I suggest you wouldn't like them anyways. They are not bad but I just don't like that he is starting this new style of modern trap. It's just not Eminem in my opinion. Regardless of that, he is still one of the best artists out there.