So one of my christmas presents was the new Bose in-ear headphones.
Since I moved to the UK and started listening to music in quantity I've always had strictly average sound hardware -- a laptop, then a series of cheap sound cards and speakers, and finally an iPod with some £20 Sony in-ear headphones. So the difference for me from my old setup to these things was pretty extreme: they're amazing. It's like having a completely new music collection full of songs that are vaguely familiar but are a hundred times richer.
I initially noticed the difference because I got into a frenzy of re-rating songs: suddenly songs I'd not cared about were sounding like 3-star songs, all my 3-stars were going to 4 and 5 stars, and then I realised it was just that everything was sounding much better. I had to start listening to my entire music library from scratch: every song is full of new subtleties and background noises and basslines that I've never heard before, and I'm having to restrain myself and be a lot stricter about what gets stars, otherwise everything is going to end up in the 5-star category.
So, yeah, I recommend these headphones. And nobody's paying me to say so.