If you're looking for a nice set of headphones with clean sound that are comfortable to wear for hours at a time, check out the Sennheiser HD-280 PRO Headphones. I picked up a set on Amazon earlier this year, and simply love them.

They are dynamic, closed-ear headphones meaning they won't bleed sound out around the over-ear cups. They are light-weight and comfortable. My one dislike is that cable is coiled instead of straight. That's a personal preference, though, and one not everyone shares with me. If you listen to music or podcasts a lot, you can't go wrong with these things.