Correction: Edition 9, RS-1, MS-Pro do not require an amp, so I'd just put a 2.
Under more than $500 you can add an IEM section:
Westone ES-2
Ultimate Ears UE-10 pro
Ultimate Ears UE-11 Pro
Sensaphonics 2X-S
You can add Stax SR-303, 404 in $300-500 section
Stax SR-001 probably should fall into IEMs <$300
Stax SR-003 can go into the same section as SR-001 seeing how it is identical.
All of the above can require amps, but it makes sense to add that SR-001 comes with an amplifier, and all the others are generally bundled with them also.
Also Stax Omega 2 in greater than 500.
Added all of the stax phones and made a "0" option for headphones that generally include an amp.
Great thread!
Too many posts about recommendations here, almost spam, this should be sticky. (READ BEFORE ASKING FOR RECOMMENDATIONS)
xD
Adding specifications about highlights and downsides of each headphone would be very helpfull.
Thanks! I added all of the info about Headphones I have heard, so others need to chime in with a short snippet about their headphones. I will be adding the hd580 and rp-21 after they arrive this week.