Head-Fi newcomer here.
I'm a big hip-hop fan. Having recently put subs in my car, and owning only ibuds, I wanted a pair of headphones with more bass. Being a college student, I also didn't want to spend too much, Googling around led to this site and this thread. I narrowed my choices down to these and the Sony XB500s. As I listen to some ska (Reel Big Fish, Streetlight Manifesto) in addition to hip-hop, I pulled the trigger on the HTF-600s. I've been very happy with them. While they don't enhance the bass on every song like subs do, they do a great job of bringing the bass out in bassy songs. I have found they do not sound quite as good at very low volumes. I was pleasantly surprised at how awesome ska sounded on these as well the first time a ska song came up on shuffle.
Now I see why everyone says ibuds suck so much.
Thank you everyone who offered their opinion on the HTF600s, and thank you Dsnuts for introducing them.
I got my pair in November, and they still haven't lost their flavor a month later...