Lately a lot of Hip Hop, basically anything produced by; J Dilla, Pete Rock, Black Milk and Madlib, its perfect to listen to during the grind, pretty relaxing beats.
Few tracks that show exactly what im talking about;
http://www.youtube.com/watch?v=BBV7RW8nfVw
http://www.youtube.com/watch?v=O1jpKianXqc
http://www.youtube.com/watch?v=3qyT4Hxl4ck
Apart from that i listen to most artist that are signed with Rhymesayers Entertainment and pretty much all decent Hip Hop, mostly from the 90s though.
Other than hip hop i listen to jazz, trip hop, ska (sometimes, keeps me in a good mood) post punk revival, indie, rock.
Huge Interpol fan and i love to listen to this when im grinding, also keeps the stress level low, same goes for Tame Impala, pretty young band from Australia making psychedelic rock music, really amazing.