If you have trouble finding earphones that actually fit you, these Audeo Earphones might be a good option for you. And even though the headphone market is pretty over-saturated, these are worth mentioning.
To accompany your MP3 player, these headphones come from a company called Phonak. They're based in Stafa, Switzerland and these earphones look to be rather comfortable. In fact, the company claims they can be worn for many hours without hurting or becoming irritable.
These earphones are also interesting because they are tailored to allow for lower volume listening while maintaining clarity. This greatly reduces the chance of damaging your eardrums. Outside sounds are also blocked out, meaning you don't have to crank it up to hear your tunes. You can try out the Audeo Earphones now. Both with with any 3.5mm player.