Currently I have a few headphones:
I used to have a pair Beats Studios, but I gave them away. I liked the sound, but they were uncomfortable.
And the following amps/DAC:
I like the sound of the HD598 but not sure if the HD600, HD650 or HD700 will make a huge difference. I am also thinking about the HE-500 or DT990. For an amp, maybe the Valhalla. I am mostly considering the Sennheisers because they seem to be the most comfortable.
My budget could afford any of these. I may even get two headphones for the different types of music I listen to. I listen to music on my computer with a Titanium HD sound card or through an iPod.
Most of the music I listen to is classic rock with a touch of R&B, Rap and country.
Are there any others I should consider?