really depends on your application. if you plan to be using them in the field you need isolation. the etymotics can't be beat, however if you can spend a little more dough, i would recommend the 4p's over the er-6's. if you plan to use your headphones for playback only, isolation is not so important. i would recommend you use actual headphones and not earphones for this purpose, b/c you will get better lows. I say sennheiser for home and etymotic for field.