Apple’s iPod is one of the most popular mp3 players on the market and it works seamlessly with iTunes, but there are many other devices that also allow users to download music through iTunes.
A growing number of car stereo units can play songs purchased via iTunes as well. Androids use Google Music, rather than iTunes, as their default music service. Since many users now download digital files directly to their cell phones or mp3 players, it can be difficult to know which devices work best with iTunes.
This list provides a good place to start!