Grado SR-225 or Sennheiser HD580?

I think my SR-225 are comfortable. It is easy to alter the tightness against your head, if needed. FWIW, my hat size is 7 1/8. Maybe some of these guys have a big ol' head, or something.
[:)] Charlie

HD600's over HD580's for sure. The 600's have crisper resolution, better frequency extension, and more natural, better integrated sound overall.

The SR series are a little darker with way less rez than the RS series. If you are serious about headphone listening, I would suggest you have a listen to the RS 2. They are about the same list price as the Sen 600's, but IMO, have better rez, bass and truer to timbre.

However, if I was to choose between 225 or 580's it would be the 580's. But again, I would spend more and get the RS 2's.

Depends on your taste of music my friend. If I were you I'd get the HD 600 since they're really a more "rounded" headphones meaning they can be for listening everything.

Be warned though! These headphones really shouldn't be listened unless you have at least a couple hundred dollar headphone amp + preferably new cables to replace the stock ones such as Clou cables, maybe the new cardas?

Note: http://home.t-online.de/home/meier-audio/
Here's a good place to buy HD600s as well, also see www.head-fi.com for more info on headphones in general. ;)

Sennheiser has the better quality in sound.