It looks like you are a picky buyer like me, which is good when there are so many choices!
I might have some points that come a little late, now that I see your list, but here we go...
I have both the ESW9s and D2000s. In terms of bass, they are both great, but you are going to need an amp for the D2000 if you really want powerful bass. The ESW9s on the other hand work great straight on my iPod, although I now use a Fiio E07K for a portable amp, but it is not needed if you don't want one. From what I have read the ES10 is not as warm as the ESW9 and might be a little more reveling if you aren't playing the best quality files. I think if you can find either for a decent price on the used market I would grab them (I got my ESW9s from ebay). If you are doing a lot of moving around though, I felt neither pair stayed on my head that great, still very comfortable.
Another suggestion are the Sony MDR-1R. They are a little larger than the ESW9s but stay on my head very nicely when I am walking about. Even easier to drive than the ESW9s and more bass, but lose some clarity in the mid range. The highs are smooth, but cant't compete with the ESW9s, which sound amazing with female vocals. They are about $300 but I got mine on ebay for cheaper. The included cable has iPod controls as well.
I know selection is hard, but if you are up for buying and selling on the used market you can try many headphones and lose much money reselling.
I'm not as picky as I am indecisive. The main thing for me is for the headphones to be the most revealing, crystal clear, comfortable, look good, and semi-portable (I think even my Denon AH-D750's are portable enough).
I wouldn't really consider the Denon's anyways, since: 1. I already have a pair of Denon's so the sound signature might be a bit similar 2. All the Denon's are Made in China nowadays, even the ones that cost over $1000, where as a $150 pair of Beyerdynamics are made in Germany and a $150 pair of AT's are Made in Japan. I don't respect Denon as a company since they want to line their pockets a lot more than AT or Beyer or other companies that choose not to outsource.
The Sony MDR-1R is likewise outsourced to Thailand. However, the MDR-SA5000 is Made in Japan and is only $500 new (maybe $200 used) but it is unfortunately Open Back so won't work for me...
Looks wise the ES10 is number one for me, especially with that Titanium housing, looks stunning, but the ESW9 looks good too, they both have a rich look about them. I feel that Audio Technica with the E series is so amazingly affordable considering the materials they use and the fact that they are made in Japan with more expensive labour. They use Titanium, Real Wood, Real Leather (not pleather), etc... And from what I hear they are super comfy and portable (although can break easier than others).
As you say maybe I should start by buying used and cheap. Maybe I should see what I can get as the cheapest. The problem is that I can get the Custom One Pro and A900X NEW for the same price or cheaper than the DT770 Pro 32ohm or ES10/ESW9 USED... I know they are inferior and I would just rather buy the best I can afford straight out, so we will have to see what I can get from eBay and the classifieds here. Already found some ESW9s, a lot of them in fact. Just wish I could try them out so I don't have to resell them if I don't like them....
BTW does the recabling actually do much to the sound? I guess this is subjective, but there are a lot of forum members that recable. Also even though I would prefer headphones that don't need to be amplified, I am sure that ALL headphones will sound better amplified, that said I might actually buy a headphone amp eventually for the office such as a Schiit (since they are made in the USA, look amazing, and have great build quality and are affordable).,.