Headphones

[leo]

Headphones can sound surprisingly good but like with a speaker based system you need a good amp and headphones to appreciate it.
A good pair of headphones can also reveal details that SOME speakers miss

[Russell Dawkins]

A wild card here that may well be worth listening to is the Audio Technica ATH-M50. Without doubt the best bass I have yet heard in a headphone and very natural from bottom to top. Convenience features include a slight folding ability and a padded pouch to keep them in. They retail for about $180 in North America.
Some very serious engineers, like George Massenburg, endorse them.

http://tinyurl.com/3awa5l

Big bonus is they're closed back, so can be used on 'planes to good advantage.

I am an early Grado adopter, but abandoned them in favor of the accuracy (and isolation) of the Etymotic Research ER4S. I like the AKG 501 a lot - haven't heard the 701 but am told by an AKG tech it is the best sounding of the whole lot - even better than my fave, the 240DF.

Grados to me are like JBLs - fun but not all that accurate, tonally.

[kt66]

my fave ever headphones are the Beyer DT990 pro, I much prefer these to my HD600s

[Filterlab]

Good cheapies are the Sennheiser PX100s, really very good for 30 notes. The slightly more expensive (£200) Beyerdynamic DT990s are very good indeed, but discontinued now.