Headphone suggestions...here comes another one

I need some head phone suggestions... I had the Beats by Dre right now however I can't listen to them for long because I get headaches/nausea from the noise cancellation technology.

Basically I'm looking for something that is comfortable and that I can listen to for long periods of time. I'm not sure what qualities in a headphone would allow one to have them on for long periods of time???

I was looking at the HD595 and Denon D2000's... mainly D2000's but I heard the HD595's were comfortable?

I'm not going to use these with an amp (for now).

I listen to hip hop, r&b, jazz, some classical, and some other genre's but those are my main ones. I don't need some blood vessel popping bass, but I'd like some CLEAN good bass... bass is still important to an extent.

PRICE RANGE - $200-225

I would have to find some D2000's used...

Another suggestions would be appreciated... just give me some model numbers or anything and I can do some research, but any comments would help!

Thanks in advance!



EDIT
I'm pretty much looking at the ATH-M50's and SRH840's right now. The are a few others (Beyer, Ultrasone) that I'm glancing at... but the first 2 are my focuses. The first two can be had for almost half of what I'm looking to spend...maybe get an amp?

The only thing is, I want it to be portable. I don't want to lug around another device/piece (amp)...

These look interesting!

I almost want to get the Grado's AND these with all the chatter going around with the grados. However, I still have a bit more price range... the ATH-M50 can be had at $125!

I've read that there are some comfort question marks on these? As this is one key factor, I want to make sure the headphones are as comfortable as possible...

Thanks!