3-d sounding headphones.....

ANy cans that image like mini-monitors...had Grado...and they are very nice...but looking for something a little fuller and more dimensional...Sennheiser? Akg? Ultrasone? $200 max...can go used
First, you may want to check out headfi.com for the best feedback and recommendations on cans. Second, I just got some JVC Victor 1000s that are great, but for a lot of money ($1,000 new and only avail. in Japan) but there is/was a used pair here for $500. Not your typical "JVC" stuff, but real good cans. Third, what are you listening to them through? A good headphone amp can make all the difference.
If I understand your question, there are two factors coming into play. First is the recording. Binaural recordings may help the imaging, or other recordings where the microphones were set up specifically for headphone or earphone playback. The other factor, for ordinary stereo recordings, concerns the geometry of headphones and where the sound is coming from, that is, the drivers are directly aiming into the ear from the sides. There might be some headphones out there that address this by putting the drivers in front of the ears, but I'm not aware of any, and they'd probably be very bulky. Until you get the sound coming from the front (or a recording made to replicate the how your ears pickup sound from the sides), you're going to have headphone imaging.
Ultrasones are incredible in this regard.
I don't know what you mean by dimension. If that means depth and width...you're not going to get that with earphones. You will get much better clarity, evenness of sound and lots of drawdroppingly good stuff from earphones, but the naturlness of speakers, and real instruments in real space can not be had. I agree with CKoffend. No one knows as much about headphones as do they. Just reading their website is interesting and factual.
Grado GS1000s have a big, open sound with lots of depth.
I do not know for the $200 budget. If you can ever find a pair of AKG K1000s used, they redefine the headphone experience; but they are more of an ear-speaker set close to your head than really being a headphone.
Sennheiser 650's... There is a good reason why they have the reputation as one of, if not the, best sounding headphones out there.

You will need an amp for them.
imo..for 3d so to speak, headphone amps have a bigger impact then headphones....
I find that one can achieve great sound staging with headphones. I am not an expert on headphones by any means. Last weekend I was delivering a pair of JVC Victor HP1000 headphones (I bought 2 pair, sold one as my wife or son would refuse to wear them due to their size) to a gentleman here in Michigan. He owns about 5-7 pair of top end headphones and offered for me to listen to each of them.

Of all of his headphones, some of the most highly regarded in the industry and even mentioned within this thread, I listened to one pair that I (based on my likes) found the most appealing. These were a pair of modified Dennons (I believe it is the 500 model, but am not 100%). He had new wooden cups made for them in Australia (after buying blocks of special wood himself - I think from Hawaii). He then modded the area behing the driver with a special dampening material. Enough of those details . . .

In the end, when I put these headphones on, listening to the same piece as with all the other headphones, I literally turned around to look at the area where the sound was coming from. It was that real and that far away from me. I honestly thought the headphones were turned off and the sound must have been coming from a pair of speakers off to my right (obviously having a full band there would not have been possible). This being said, was one of the most natural sounding musical listening experiences I have ever had in terms of accuracy and my perception of reality.

This being said he was playing the headphones through a Wadia transport to a Wadia DAC to a good headphone amp of which the brand was I do not recall (he had several RSA amps). Very impressive to say the very least.