I would say iTunes is. They certainly have invested a lot into the core playback engine of iTunes and its quality.
For example they have their own loudness analyzing specification called Sound Check. A music player having its own loudness specification and analyzing algorithm is very rare! Most players don't have support for analyzing at all and if they do, they usually use the original mp3gain algorithm to calculate the ReplayGain value (but as that one is GPL, this is only for GPL players).
The overall audio playback quality is quite good.
Also they have a lot of other advanced features.
E.g. the iTunes DJ mode is actually not so bad. The algorithm behind it works quite good.
They also have a remote interface where users could vote for different songs and the song with the highest votes will get played next.
For example they have their own loudness analyzing specification called Sound Check. A music player having its own loudness specification and analyzing algorithm is very rare! Most players don't have support for analyzing at all and if they do, they usually use the original mp3gain algorithm to calculate the ReplayGain value (but as that one is GPL, this is only for GPL players).
The overall audio playback quality is quite good.
Also they have a lot of other advanced features.
E.g. the iTunes DJ mode is actually not so bad. The algorithm behind it works quite good.
They also have a remote interface where users could vote for different songs and the song with the highest votes will get played next.