I was looking for the Sennheiser HD 600 appreciation thread and couldn't find it, so here it is.
When recently listening to some of the current flagship headphones (at time of writing this includes the Sennheiser HD 800 and Beyerdynamic T1), each of the stockists I went to had the HD 600 on hand. Having never heard the HD 600 before, I decided to try them. Whilst the flagships 'wowed' me in many ways and microscopically revealed details I'd never before heard in music that I'd listened to for years, I found myself coming back to the neutral-sounding presentation of the HD 600, which worked really well with every recording I heard through them and have since heard through them since purchasing them. For me, there's little to fault with the HD 600.
I love the HD 600 - they're awesome!