for the most part over the years i have tried dozens if not more different music applications and never really been happy with any of them. I ended up sticking with Windows Media player for the most part however, for the last few years i just upload all my music to google music and then either use the app on my phone or i just go to the website on a computer to listen to the music.
as far as an offline solution goes the best one i had used for over the years ended up being Songbird however, it was discontinued last year. They recommended Nightingale for a replacement as it was based on the original songbird code.
personally thought right now i am sticking with google music.