The Sennheiser HD-239 is good sounding. Good tonal balance. It has deep and full bass. It's a bit veiled but for mp3 played through iPods this should be more than enough. These are compact and pleasant cans.
The best earbuds i have used with my iPhone...at a reasonable price are the altec lansing Muzxseries. They sound pretty awesome for a sub 40 dollar headset