http://www.musiciansfriend.com/pro-audio/sennheiser-hd-280-pro-closed-back-headphones?src=3WWRWXGP

I have both the Sennheiser HD 280 Pro, and the Grado SR80

I like the sound of the Grado far better than the Sennheiser. actually, i like the Grados better for everything, except when i need isolation. the grados are open air headphones, and just sound bigger and airier.

i also tested the Sennheiser HD 600 (150 ohms), and the Beyer Dynamic DT880 600 ohm. and i don't think there's really anything special about higher ohm rated headphones, other than the ones i tested just being higher quality (of course they were 3 to 4 times as expensive).