Ok, this looks like a fun thread, gonna chime in with my 2c:
- Sennheiser HD800. Yes, it's a fantastic headphone but probably the worst sounding and the most amp-picky of anything even close to its price. It's very sibilant and analytical sounding for such a pricey headphone. Requires a great Eddie Current amp or the like in order to sound fantastic. So as not to make this about being over-priced rather than overrated, I'll say that I see tons of these at head-fi meets but don't usually spend too much time at those tables.
In the general public:
Anything by Beats! Enough said.
- The HE-Audio Jade. I guess every pair sounds a little different but the ones I've heard rival the HE90 for best can in the world.
I have to agree with the Sennheiser HD 800; every time I heard it, I thought it was harsh, lifeless, and sibilant even when on a warm tube amp(though it did help). I don't consider it neutral or natural, it's too bright and has a recess in the midrange and in the end you have to tailor the system to it and mod it to make it more neutral. A neutral headphone shouldn't sound bright and lacking in warmth on a neutral system like the HD 800 does. It seems to be one of the most popular TOTL headphones here other than the LCD-2. I found it a disappointing deviation from the sound signature of the previous Sennheiser top of the line products. It isn't like the HD 6x0 at all, but rather more like a glorified K701 with a Senn flair to it. It was the most disappointing uber headphone I have heard, I'm sure it will sound great on the right system, but the fact you have to tailor your system like that so much to the headphone ruins it's value to me.