HD 800's: Couldn't be happier with these headphones, in a different league from what I've owned or own presently
HE 500's: Most accurate headphones I've ever heard to my ears; very natural. Nice bass impact and bloom.
LCD 2 rev2 (previously): Fun sounding headphone with nice bass and midrange presence. Very mediocre in the upper mids and highs. Not necessarily my cup of tea; find it overrated personally. Not comfortable.
HD600's/ HD650's (previously): Very good considering the price you can get them for online. Very natural sounding again but not as much microdetail as the hifiman. Slight preference to the 600's.
IE8's: Very fun and dynamic headphone. Unnatural amounts of bass, but it's fun when on the go/ daily commute.
Fostex T50RP Paradox: Most neutral sounding headphone I've ever heard. Best closed can I own... Comfortable. Easy to EQ. Lacks detail retrieval due to driver limitations.
Grado Alessandro MS2i: Meant to be magnumized but got HE500's instead. Very dynamic headphone, amazing bass. Use it to practice bass guitar.
Hifiman RE0's: For 70 bucks these are fantastic. Kind of lean in the bass department, but good when eq'd.
Shure SRH 440: What probably started the addiction. Very good price/performance ratio. Detailed and clear (sterile) mids. Lacking bass.
Shure SE215: Amazing comfort and isolation. Good build. Sound quality is good for the price; fun sounding signature.
And also, something I've owned but could not use at the time I owned it
:
AKG K1000's: Got them by luck for a ludicrous price and sold them. Did not have anyway to use the xlr plugs during the week I owned it. Too bad.