Hmm.. I don't think I'm going to buy an amp. I'm just going to use my headphone for casual music listening from my iphone. 

Which of those has the best sound quality? Do they worth their price? This is probably going to be my first real good quality headphone.. I'm planning to spend around 300 dollars, I listen to all kinds of music, and I'm pretty concerned about look too. Are there any suggestions? THANKS!!