Avoid the Grado SR 60/80 if you can't have noise leakage. They leak more then any other headphone I've used (and I've used a lot).

The Sennheiser PX100 is my favorite sounding pair for under $50. They, too, will leak sound but not as much as the Grado's. If you listen at moderate volume they may be OK in the office. One of the guys here uses those and they don't annoy anyone. But they would annoy people at the volume I listen.

I use the AKG K26P at the office. They are closed so they hardly leak at all but unlike most closed headphones they sound good. The comfort is only OK. They clamp rather tightly at first but with break in and some forced bending of the band I can wear them all day now.

If you just want regular earbuds the Sennheiser MX500 are a steal at $15. If you get the MX500 then I recommend going to Radio Shack and getting their $2 earbud foam covers. They improve the fit and sound of the MX500.

Yes, I'm a headphone geek.