Noting the standard-issue podphones' abyssmal audio quality, my discerning ears picked up a pair of Sony MDR-EX51LP noise-cancelling earbuds from Amazon. There's a radical difference in the amount of artifact [read: none] as well as a noticable change in the amount of volume needed to properly enjoy the music. It's also less likely to get me mugged on the subway, but that's a whole different discussion.

However, most consumers [especially those of the iPod generation] are not as picky as myself when it comes to their audio or its quality, and generally think that whatever comes in the package is best suited for their use, even if it means sacrificing some hearing. [Like, why would they include it if it weren't the bestest evar?!]