I'm not an audiophile, (don;t have the money to be a high-end one) I'm kind of new to this, but to answer your question: I bought my first head-fi-worthy headphones (the HD650) about 2 years ago. By then I already had over 1500 cds of classical music in my collection and a good amount of other genres especially progressive rock and metal. And I had tv speakers as my speakers.... So it started with the MUSIC and it still is about the music.
Now I have a somewhat more decent pair of B&Ws 683 as my speakers (more for tv really). I rarely hear music in loudspeakers at home. I use the sorry speakers in my car. So you can see it's about the music, not about the sound quality. With headphones, by far my preferred form of listening to music, of course I want to get better and better sound. Once I got my Sennheisers HD380 I started discovering there was a lot of aural information I was missing... Then I started trying to find the perfect sounding headphone for MY tastes and now one day I want to hear other options... But it's still all about the music. Norah Jones (sorry, I don't like that type of music very much) will not appeal to me even if it wins recording of the millennium in all galactic systems. I will keep my sorry-sounding recording of Beethoven's 9th conducted by Furtwangler in EMI till I die.
BONUS QUESTION - Is there one album that you would willingly sacrifice your entire system for if the alternative was never listening to that album again? If so what is it?
No, not one SINGLE album. Even the most expensive set I have (Solti's Wagner Ring) can still be re-purchased. Of course if they tell me I have to give up my headphones or I'll lose the chance to listen to it forever and ever, there I will go back to some crappy Sony 30$ cans...