I have a few requirements : ReplayGain support (there are still many players out there without ReplayGain)
GMMP is good as for features but bad as for sound engine. The audio is very flat and inexpressive. Unfortunatelly there's not much more players playing Opus.
TOS 8 much?
DescriptionPlayer which can play many file formats + online radio (shoutcast)* multiple playlists* plays folders or specific files* true gapless playback -- the player doesn't just skip silence, it calculates the precise amount of samples for each file, does sample-accurate seeking and playback, and gives sample-perfect result, just like CD players* equalizer with 10 bands, it's possible to make your own presets* viewing music file tags and album art* replaygain* shuffle tracks and shuffle albums mode* last.fm scrobbling using last.fm or scrobbledroid apps* plays many file formats - mp3, ogg, aac/mp4, alac/mp4, flac, ape, wv, wav, tta, mpc, sid, mod, s3m, nsf and many more* automatic CUE support, with splitting images into tracks, and playing them gaplessly* online streaming radio (shoutcast/icecast)* full unicode support and automatic charset detection* 4x1 widget (available as a separate download, search for "deadbeef player widget"* you can choose one of three themes, Dark, Light and LCD* works on android 1.6 and higher* headset media buttons support* plays files with up to 192KHz sampling rate, including 24 bit and multichannel files* supports install to sd