Ok since most of ns knows absolutely nothing about headphones don't listen to them.
There were a few good responses in here though.
Grado makes excellent headphones, most are open air though, which means people around you will be able to hear your music, so not great for crowded areas, but they will be very sick headphones.
Sennheiser makes great stuff as well don't know a ton about them other than that they are nice and liked by audiophiles.
I have AKG 81 DJ's, which they don't make anymore, but I think they make a similar model now anyway, they were like $70 for me and I love them. They are not active noise cancelling but they keep outside wounds out very well. The bass is really good too, better than any skullcandy shit or Bose, especially if music is coming out of a CD player, computer, or amplifier/stereo.
Sony makes some good stuff too, stay away from their low end stuff though, I'm not sure about models of Sony's that are good but if you spend $100 on Sony headphones they will most likely be good headphones.
Bose are shit, don't buy them. They advertise them as the "ultimate in luxury" headphone or whatever but in reality they are not good heaphones, especially for what they sell them for, it's all marketing.
I've heard Audio Technica makes some good stuff too but I know next to nothing about them.
For real information on headphones check out: http://www.head-fi.org