If you're looking for headphones, you might want to take a look at Dave Rat's work in recent years as he tried to pick out a new pair. There are youtube videos he created, along with quite a bit of writing on the subject. Even he says in his videos that people have questioned his measurement method / technique, but it's interesting to me all the same.
I personally use the Audio Technica ATH-M50 cans for my everyday work, but I also own maybe 6 other pairs of high quality cans from Beyer-Dynamic, AKG, Ultimate-Ears ... and even a pair of the deluxe Bose Noise Canceling phones that my girlfriend gave me for christmas.
Gotta admit, that although I wouldn't use them for professional work, the Bose cans are a pleasure to own and use for casual listening. A few carefully placed pieces of gaff tape took care of the Bose logos and the stupid (on) light... much better now.
Here is the link to Dave's blog with quite a bit of info... http://www.ratsound.com/cblog/archives/369-The-Mighty-Headphone-Quest-Part-7.html