For true noise-iolation and maximum sound quality, you really need a pair of "over the ear" headphones, like this lightweight model from Monoprice.

These headphones are ideal for portable applications when you want to get the best sound and really don't want to be interrupted by outside noises. They are vertically adjustable to about 1" on each side and fit close to the head. Combined with the light weight it means you can move around a bit and not have them fall off your head.

The earpieces are fitted with thick, comfortable padding which improve the fit against the side of your head and helps keep outside noises from interfering with your listening pleasure. A 50 mm driver and 102 dB sensitivity ensures that these phones produce good volume and clear sound reproduction at all frequencies.

The 47" cord is ideal for portable applications or for use with a laptop computer. The 3.5 mm plug is gold-plated for maximum conductivity and for improved resistance to corrosion over the more common tin- or nickel-plated types.