[chiph]

Noise isolation & travel: Shure SE215 earphones. Good quality at a reasonable price. You can coil them up into a zipper baggie to keep them clean, prevent tangling and to reduce the amount of space they take up in your carry-on.

Sound quality & home office: Sennheiser HD485 (which seem to have been replaced in their lineup by the HD558's) Doesn't block any noise, and people can hear what you're listening to. But excellent bass response and they have a long cord. Comfortable for longer wearing sessions.