I'll be the first to admit that most popular hip-hop music is rubbish (Puff Daddy, Snoop, Jay-Z, Lil' Kim, et al).
But people, until you've sat down and listened to something like Pharcyde, Black Eyed Peas or Mos Def, please do us a favour and hold your two finger typing. This music is fun and, yes, sometimes even thought-provoking and you can bop your head to the beat.
My list of favs would be too long, but if there's one composer I can recommend it is Richard D. James aka. Aphex Twin, a musical philosopher, a master mind.