Try most of Nas' earlier albums ... Illmatic and Stillmatic ... it might be blasphemy but my personal favorite is It Was Written. God's Son was also good.
While King, Paper Trail and No Mercy are his best albums, Trap Muzik by TI is also very thick, funky and Southern.
Not the club banger type rap which is good to get pumped up, this is what I blast when I'm on the cruise. It just keeps you chilled and focus.