Poweramp really is the best and sounds the best. The only reason I stopped using it is due to the lack of the "short audio focus change", which will dim the audio -- rather than stop briefly -- if another notification comes through. That feature is a must have for me, especially when driving and using GPS.
Gone Mad Music Player (GMMP) has the short audio focus change and equally as many features, but doesn't look as nice. And, although I can't quite pinpoint it, the audio isn't quite as crisp as Poweramp.
Google Play Music has really nice, crisp audio. It also has the short audio focus change, but no customization; and the EQ is very limited.
Your "THANKS" are not necessary, but I would appreciate them when due.