I 2nd the vote for DMX - It's Dark and Hell is Hot
Eminem - The Eminem Show - Picking the best Eminem album is really hard to do cuz they are so different. SSLP - yeah, it was great overall, but listening to it now you can tell that he wasn't very polished. The beats didn't fit well with his voice. MMLP - that was way hotter and is more popular, it some SSLP-esque tracks, and it doesn't really have a weak point. But for me Eminem Show is his finest. I think most people would vote MMLP, but it's all about how you like your Eminem, I personally want sick rhyme after sick rhyme, all killer, so to speak.
Those are really the only 2 that I would add. I'm way picky on what I would consider to be a 5 mic album. I can't really say that any of those don't deserve to be on there, as I haven't heard them all completely. The only one I would throw off, of the ones that I heard would be Chronic 2001. Way too many tracks where he was trying to promote new rappers.
Since I don't think everyone will be as picky as me about this I will throw in some I think are ALMOST there, 4.5 for sure.
Tech N9ne - Absolute Power
Eminem - The Marshall Mathers LP
Master P - Ghetto D
Juvenile - 400 Degreez