VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
Celluloid - Celluloid (formerly GNOME MPV) is a simple GTK+ frontend for mpv. Celluloid interacts with mpv via the client API exported by libmpv, allowing access to mpv's powerful playback capabilities.
Roon (Music Player) - Roon is a music playing application for audiophiles
SMPlayer - SMPlayer is a free video and audio player for both Windows and Linux that allows you to play almost all media files without having to install additional codecs. Read more about SMPlayer.
Jajuk - Jajuk is software that organizes and plays music using Java.
QMPlay2 - QMPlay2 is a video and audio player which can play most formats and codecs.