Good headphones to go with MP3 players and computers

I didn't spend money and time on headphones for me to listen to music on MP3 players and computers at the beginning since I thought the sound from computers were too lousy to justify expensive headphones. However, after listening to music many hours daily for a while, I got frustrated with poor sound quality my Sony ear buds offered and started to do some research online. I found this Koss Portapro had pretty good reputation and Amazon had it for about $34, so I purchased a pair to try. To my surprise, the music sounded much better than I expected suddenly when I switched to Portapro. It was then I got hooked. I started to do more research and started to build my own DAC and Headphone Amplifiers (I am an Electrical Engineer with extensive design experience in test instruments and communication equipments). Following the recommendations on GoodCans (I found the author shares a lot of tastes in sound with me) I upgraded to Grado SR60 (now discontinued and replaced by SR60i). SR60 costs about $70, which offers great performance that not many competitors can offer. Amazingly, these 2 models were designed many years ago, and they still have about the best performance/cost ratio. They are also easy for computers/MP3 players to drive without an extra amplifier. I also use Koss KSC75 when I am traveling. I purchased these under $5 from RadioShack on sale. The sound is almost identical to Portapro with slightly stronger treble and weaker bass (because it does not sit on the ears as tight as Portapro with pressure from the headband).

Lately I've been using JVC HA-RX700 at work, which provides some sound isolation so I do not hear too many phone conversations around me. These have deeper bass than Portapro and SR60. These can be found at $35 online. This model is more sensitive, i.e., outputs higher volume than Koss and Grado products.

For listening inside flights, I use JVC HA-FX66A or Sennheiser CX300. These do not provide super isolation as more expensive models do, but they are good trade-offs between sound/isolation and cost.

If anyone asks for recommendation, I will not hesitate recommending any of the 4 bigger models I mentioned here. However, they are not very pretty or fashionable, so it may not be something suitable if you care more about look than sound and music.

It is important to note that these headphones give you best sound when your music is near CD quality. If you listen to a lot of music ripped at low rate or with noticeable distortions, these headphones will show these flaws with no mercy. I do have a recommendation for these situations - Sennheiser HD-555. I found one under $70 after mail in rebate. HD-555 is reasonable balanced, i.e., flat response over frequency, but lacks details that is revealed by the other headphones I recommended above. This is the reason the music sounds smoother, but it is also the reason the it is not on my favorite list, because I hardly listen to any music ripped at low rates.