I've never bought based solely on sound quality, as most earbuds hurt too much to keep in for any length of time. Granted these are poor quality earbuds and more expensive ($100+) would likely be a better fit.
Apple's are the same way. Hard plastic is the worst thing ever to my ears, and causes them hurt within minutes.
I stumbled across these, Philips HE591 Surround Sound Earbuds (Black), and I haven't looked back. They sound great, but more importantly, they feel great. I had read a number of comments on them being too large for some peoples ears, but for only $20 I decided to try them.
Expensive earbuds may sound like a dream, but these do the job damn well for me