Aesop Rock is some great independent hip-hop that not only surpasses what most people bring to mind when they think rap, but he'll also get you hipster brownie points, as he's one of the most critically praised underground hip-hop artists in the business.
He's released several albums, but I'll link my two favorites below.
Aesop Rock - None Shall Pass
His most recent album; features a more electronic/sampled sound then his previous work.
Aesop Rock - Labor Days
His most critically praised album; many of the songs focus on the daily struggles of lower class blue collar workers.