i'd have to recommend the headphones i use.....audiotechnica ath-m50s. m50 is coiled cable, m50s is straight cable. they are studio headphones which means they are very balanced.
you do not have to use an amp with them as they are low resistance, but getting a soundcard with an amp for the headphone jack will make them sound a little better than the great sound they give you without an amp.
i have used mine unamped on my phone, mp3 player, laptop and pc....and amped out of my receiver. sounded great in every case.
if you dont like audiotechnica, i heard sennheiser makes a nice product as well.