http://market.android.com/details?id=com.tbig.playerpro
PlayerPro is my recommended choice for audio playback. The PlayerPro let's me customize the UI, edit playlists and this is what really appealed to me, allows for editing and uploading of ID3 tags (and that even includes album art and lyrics). And I haven't even EQ, or the DSP plugins yet. This tottally made my day