So I have some pretty decent headphones. I am no audiophile, but I can describe the experience. With a pair of quality headphones, you get a new sense of location that you wouldn't get otherwise. Not just right or left, but how far right or left. You will hear things in songs you didn't notice before because they were too compressed by cheap headphones. You will actually hear the bass player. You will get a new appreciation for proper production. I really recommend getting a pair of good headphones if you like music.
I did some research when I was in the market for headphones and landed on the ATH-AD900x. I went for open-ear because they were supposed to have better soundstage, and I like being able to hear my surroundings as well. Listening to music and playing 3d games was almost a whole new experience when I got them. I could pick out instruments and sounds that I couldn't differentiate before, everything sounds so much nicer and it was completely worth the money. I grabbed a cheaper Xonar sound card as well, since supposedly theyre good for pairing with headphones for 3d positioning in games, and have a built in amp. All in all, if I had to pick peripherals to spend the most money on, I'd probably put Headphones up top, then monitor, mouse, then keyboard. It made THAT much of a difference.
Sounds marvellous. What bothers me about many headphones is the padding they have around the soundchannels. From what I understand, they are to prevent outside audio from polluting the inside audio, but every time I tried headphones with them on, my ears sweat far more than they ever should. Considering I often listen to the music for hours on end, this is a very inconvienient circumstance. Do you have any experience with that, and/or with how to avoid it?
These headphones don't make my ears sweat in any significant way, but YMMV. I use these at work all day. I do need to take little breaks every now and then because the pressure/weight gets a little annoying after hours of use, but this hasn't bothered me either. I really love these, and I have friends who have the same model/the next model up and love them, but again, YMMV.