Get the RE0. I have them, they're great for rock. They bring out all the details and the bass is accurate and not overpowering. They'll run you $79 + ~$3-5 shipping from here. They're some of the best headphones you can buy for the money right now, on sale from $170.
Radius iPhone 3G In-ear Earphone with Mic (Extra Bass Music) seems not bad for around 25 including delivery from Gadget gear and they got good reviews as well, worth a try IMO