You guys need to adjust this to YOUR ear. Of all things subjective sound is probably the most widely varied. Like the "DJ" setting above. Is anyone really surprised that he bumped up the bass and dropped everything above that? DJs are the LAST people I'd go to for advice on anything sound quality related.
Also, there is plenty of good hip-hop and rap that's well recorded. You just have to know where to look. Modent pop/Top 40 stuff is probably the worst stuff available since it's all compressed to sound good on earbuds.