I would go with the sennheisers hd500, but thats 'cause I listen to more classical music and jazz. If you need a little more "power" and not as much clarity, get grado's. Check out the info on both companies at
http://www.headphone.com not only do they have good reviews, they have decent prices too. If you can, the best for rock are probably the grado 225's. But looks like you want to spend as little as possible. In that case, you can't go wrong with the Grado sr60's for $69.