Originally Posted by
Aborted
One of the resident audio dudes here: ATH-M50's are a great first choice, and one of the best headphones to start with.
Alternate choices would be V-Moda Crossfades, Sennheiser HD 598s, and Beyerdynamic DT770's.
M50's are solid all around, and will definitely get you started in the direction of HQ audio.
V-Moda Crossfades are built sturdier, and have more bass, but are less neutral and therefore don't display the audio in its 'truest' form.
HD 598's are full open-back cans, so they aren't very good at keeping background noise out (or your noise in), but are more natural sounding and neutral.
Beyerdynamic DT770's are great all around phones, that are extraordinarily comfortable, and have great sound (though the burn-in time is long.)
Source: Owned all of these headphones.