Add me to the HD580 lover's list. They are easily the shining point of my little collection. My head-fi addiction started with PX100s, went to KSC75s, AKG K81 DJs, and AT A7000s. I finally got my HD580s second-hand via a trade on these very forums and all the other headphones I listed (short of the PX-100s, which are now my work 'phones) are utterly neglected because of my addiction. Movies, music, TV, gaming. I do everything with them and it excels at them all. Couple my Turtle Beach Micro Advantage USB with my laptop and HD580s, and you've got economical audio bliss.
I too have a set of HD600 grills on the way and am giddy with anticipation for the cosmetic upgrade. Next, I want to swap the cable with a slightly upgraded 1-meter one, as I find the stock cable way too long. If anyone has any recommendations on that end, please let me know.