Ahh, first post!
In no particular order:
Clipse- Hell Hath No Fury (they don't get half the love they deserve, honestly, they are so nice with a pen and pad)
DMX- It's Dark and Hell Is Hot (get better Earl, i'm standin with you)
Nas- Illmatic
Eminem- The Eminem Show (you could argue any of his first three, but I still bump this one)
Ghostface- Fishscale (I'm too young for the old school Wu)
Immortal Technique- Revolutionary, Vol. 2
Lupe Fiasco- The Cool