I'm more of an iem man as I have or had the ie8, se530, fx-500, fx-700, sm3, hippo vb, sound magic pl50 (and 30), ie7, and monster pro gold. I want to listen to a good full sized can in the house though as they trump iems on average (price for price).
As far as full sized headphones I have the hfi-780 and sony v6. I had the bass monster bt770 80ohm pro (didn't like the recessed midrange though).
What I like the most are (not in order yet):
1. Decent bass (not too little but slightly above average. More on the sm3 level or above)
2. Great mids (very clear and not recessed but slightly forward)
3. Low or average treble (I don't like harsh or edgy upper mids or high treble)
4. Decent soundstage (above average if possible and average for a full sized can at minimum).
I think the sm3 has the right amount of bass, but a very little more wouldn't hurt. It has the right amount of forwardness to its midrange, but it could be a little clearer though. It has the right amount of treble for me (I don't like a lot of that treble stuff). Lastly, it has the right amount of soundstage for me (although more wouldn't hurt either). The se530 midrange is a touch too forward for me and has slightly less bass than I want. The fx-700 has a clear midrange but slightly recessed for my taste and on the borderline of too much bass and treble. The monster gold was nearly perfect except for the soundstage (slightly not big enough), and that it could have used an ever so slightly more forward midrange instead of being neutral. The ie7 is nearly perfect as well but the midrange is too pointy in its forwardness. What I mean is that only a narrow part of the midrange seems boosted forward (like a sharp peak) and not a wider mound like the sm3. This makes the ie7 sound a little thin in the midrange sometimes. The ie8 has a slightly veiled midrange (textured as some call it). I would be satisfied with the hfi-780 if it wasn't for the not so good comfort (I can't wear them for hours without paying for it) and the slight treble edginess (although I can eq it a little down). The sony v6 is also a little too bright for me.
What I want is a full sized headphone that has at least the bass quantity as the sm3 or more and no less than the hfi-780. I also want it too be very comfortable or at least more comfortable than average. I want the mids to shine and be clear and present (lush is a plus too). I don't care for treble or upper mids, so they can have rolled off treble or just average treble (but not more than that) for all I care. Soundstage has to be at least average too. I will listen to some rock (like old school hall and oates), some jazz (sade), some hip-hop, the type of r&b and pop with good vocals and decent bass, and some techno music (old school kraftwerk). I will use ipod touch 4g or sansa clip+ or galaxy s phone (whichever drives the best) with fiio e11 amp or fiio e7 amp. I will use only in the house and in my room since I will only use iems on the go. I prefer them to be under $300 but will consider nothing more than $350. I'll buy them used if I have to.
In order of preference I want
1. Adequate bass (too much isn't a bad thing if #2 below is met)
2. Good mids (clear and not veiled and neutral at min and slightly forward at best)
3. Good comfort (plan to wear about 1 hour min and up to 2 hours max per session)
4. Decent soundstage (not too narrow or small, large isn't a bad thing either)
5. Not too difficult to drive (I will be using portable amps like the fiio e11 with probably the ipod touch 4g)
What are the full sized headphones that you guys recommend that fit what I'm looking for? Note: I don't mind equing just a little if there would be no distortion whatsoever and the headphones respond well to the eq.