1.) There are no perfect headphones.
2.) Very expensive headphones have a tendency to be prone to damage from dropping (or in other words, DO NOT Fin TAKE YOUR GR8MAZING PHONES OUTSIDE YA HOUSE)
Out of my own experience, I suggest getting two sets of headphones. One, more expensive set Like Audio Technica m-50 or Sennheiser HD280 (used by Lavender Harmony and D'notive, recommended by me)
and a second set of cheaper but pretty much the same quality for listening outside your home. In there there is only a single choice.
mother fucking >>KOSS PORTA PRO<< DUN DUN DUUUUUUUUN. Unlike Beats, these are popular for a reason, it being they sound amazing. The only downside is that you shouldn't ever take them off your neck because of how not rigid they are, but you'll be hard pressed to find headphones that won't break when carried in a backpack. They come with a carrying bag but do not fucking use it cuz my sister broke them after one day of carrying in the bag.
You don't need a headphone amp if you're getting Sennheiser HD280 64-ohm, though you may want the 200+ version in which you should get them.
One more very important thing: your sound system is only as good as the weakest link. If you're going to use built-in Realtek HD with the MME/DirectX driver just stick to Sennheiser HD201. I've been using a Xonar w/ASIO4ALL for 19 months now and it's a p good thing but you should look for the Focusrite Scarlett series
Here is a detailed chart for comparing headphones:
http://www.headphone.com/learning-cente ... -graph.php