Searching for the best earbud headset can be difficult because so many options exist. The choice boils down to two simple factors, however: comfort and sound quality. Other factors exist, but they are secondary to these two important considerations. An earbud headset should fit comfortably in the ear and feature a system that prevents the earbuds from falling out of the ear while the wearer is in motion. A noise-canceling earbud headset can eliminate outside noise from reaching the ear, thereby enhancing the sound quality and even helping secure the earbud within the ear canal. Sport earbud headsets are resistant to moisture and sweat, and they are designed to secure the earbuds within the ear during physical activity.
Since you can't just take earbud headset units out of their packaging at the store and try them on, it will be difficult to know if the units are comfortable and high quality in terms of sound. Researching different models on the internet will help narrow down the search, but again, different ears will react differently to each style of earbud. To choose the best earbud headset, consider a unit that is noise-canceling, and also consider a unit that features adjustable earbud sizes or some sort of fit system to ensure the earbud will fit solidly and comfortable inside your ear canals.
Athletes may want to consider sport earbud headset units that feature securing systems which specifically prevent the unit from jostling around too much during physical activity. Some units feature harnesses that wrap around the back of the head and loop over the top of the ears to provide extra support and keep the earbuds in place. Sport earbuds are usually resistant to sweat and moisture, and they often feature thicker or high-quality wires that are resistant to damage and moisture. A thicker wire usually translates into better sound quality as well, so when researching any type of earbud headsets, consider one with a thicker wire.
Retractable earbuds are convenient for storage in a pocket or backpack. They feature a retraction unit that collects the earbud wires when not in use, preventing tangling and folding, which in turn prevents damage to the wire. While slightly bulkier than normal earbuds, a retractable unit can make storage much easier by preventing the wire from becoming tangled or knotted. Other units may feature an in-line microphone, which is useful when plugging the earbuds into a cell phone or other device that has microphone capabilities.