Sony does some fairly nice headphones. The 7506 phones have been made for years, and are good enough for a lot of people who make a living with sound. Not flashy looking, though.
MDR-V700DJ are used by a lot of DJs. I think I prefer the bass from them to the more expensive MDR-V900. More weight, less mud. (But two co-workers that tried my V900s went and bought their own.)
Sony MDR-V700DJ - Headphones | HeadRoom Audio
Either should be plenty loud from a portable player, unless you want to listen at dangerously high volumes. If so... well, the 700 is rated to handle 3000 mW of power. Perhaps that's useful if you wear headphones over earplugs in high-noise environments.
If you're after isolation, even over-the-ear headphones don't offer very much. 10 dB at 1 kHz, more at higher frequencies. Industrial and aircraft headsets manage around 24 dB but cost a lot and sometimes don't even do stereo. In-ear 'phones covered with industrial hearing protectors are effective, but not exactly stylish or convenient.
That said, I happened to check out the Sennheiser HD-280 at headphone.com... better isolation than the Sonys, and cheaper.
Sennheiser HD 280 Pro - Full Size Headphones | HeadRoom Audio
