Set one are the Samsung Earbuds that came packed with a Samsung Galaxy Note 4. These earbuds have a second ring for a micrphone (TRRS), a microphone volume dial and flat cables. Although they came free with the phone, they probably would cost you $5-6 at retail.
Set two are a pair of Earbuds branded with Disney's Phineas and Ferb cartoon show. They have rounded cables and no micrphone. They use gel Earbud tips. They probably would set you back $2-3 at retail.
Set three is a pair of Earbuds bought at the dollar store. The cables are extremely thin and the block that allowed for the Earbuds's cable to be retracted broke very quickly. $1.00. Unlike Set one and two, they do not use Earbud tips. The Earbuds Nintendo packaged with the original Game Boys looked very much like these.
Sets one and two are more comfortable in the ear than set one and can fit more snuggly. Set one, when used with a modern device like a Samsung Galaxy Note 4, sounds crisp and clear with the audio generated from that phone. Sets two and three have a hard time fitting into the headphone jack. What you hear from them sounds comparatively muffled compared to set one.
So, which set is best for listening to the Game Boy? In terms of Sound Quality, set two or three sound superior to set one. Set one will give the loudest sound, but the noise floor is also raised. The result is a constant hiss at any volume. Additionally, set one will give off a high pitched noise at high volumes and audible hum at low volumes, which can be easily be heard when no music is playing.
Set two and three will give an appropriate volume, but it won't be deafening like Set one can provide. Nor will you hear hum or the sharply pitches at the extreme ends of the volume dial. However, set two sounds way too quiet unless the earphone connector is pulled a few millimeters out of the jack. Set three doesn't have this problem, but its earpieces are far less comfortable than Set two's gel earbuds.
This is another example where the latest and greatest is not the best for vintage gaming hardware. The Samsung Earbuds deliver far more dynamic range than the cheap Earbuds, but this is a situation where an output device gives too much. I found that headphones that came with a functioning volume wheel could cut down the headphone's own volume range to mask out the worst aspects of the Game Boy's sound without lowering the volume too much. Without a volume wheel, you are left to the mercy of the earbud's default sound repoduction, and it may not sound pretty.
Even the DMG Game Boy is no audiophile's prize, it is far from it. It retailed at $100 and used a screen that was unimpressive even in its day. It did have Tetris, great battery life and a good price, so if the audio quality is less than spectacular, most people did not care. Also, after the first two years, stereo sound separation was not very noticeable with games.