First of all, I'd like to tell I'm not really into headphones, so any suggestion is accepted. That's why I'm asking for a purchase suggestion. My budget is around 150 dollars and I'd like to use headphones for symphonic metal and gothic metal music mainly (bands such as Nightwish, Epica, Tristania). But I'm also into acoustic music, opera and music scores. I'd plug the headphones to my MacBook Pro with on-board sound card, as well as my iPod touch. However, there's only one thing I'm sure about my future headphones: they must be closed.
Waiting for your suggestions, I thank you all in advance.