"Best" depends on a number of factors. What's "best" for one person can be the "worst" for someone else. Let's start by answering the following questions: - Do you have a particular sound preference with headphones? - What genres of music do you listen to? - What is your budget? - Do you have to have a removable cable, or is a fixed cable OK? - Do you care about isolation (ie music leaking out or external sounds leaking in)? - Do you care if the IEM is worn down, or do you like behind-the-ear IEMs? - Do you have small ears? Or odd shaped ears? - Do you need a microphone or music control button - Do you plan on sleeping with the IEM? - Do you want the option to use them as bluetooth earphones?