Not only the best sounding, but what are the best looking ear or headphones you've seen? I should've gotten these cool 80's retro Sony cans for the iPod i'll be getting, they were white!
grado's are nice but not ideal because the open design....i don't like when ppl play their music if i forget mine and i extend the courtesy to others.
edit: do a search we recently had a really big thread on this...i prefer the in the ear style so it blocks out other sounds but also have a pair of bose triports...they are really comfortable for listening and i'm not an audiphile so i think they sound good.
i have a pair of Sony MDR-EX71 in-ear phones. I am still breaking them in but i am very impressed so far. You can get them in white also if you are willing to get them shipped from Japan. the black ones i got were only $32 from ecost.com. The white ones will run you about $50.
If you look hard enough, you might just find a pair of white Sony MDR-D66S. But if not, the black will be good enough. It's gonna cost you $99, but do you really care about the money after dropping $400 for a MP3 player?