Alternatives Software for iTunes on Mac

Been an iTunes user since its inception and quite satisfied with it with its overall sound quality in my system. Recently I have encountered some significant problems and have decided to look for an alternative to it. Have a large collection of music on a separate external hard drive in AIFF files, 2500 CDs or albums. Currently uses Apple airport express to wireless play music from my computer through a Rotes Integrated Amp and Monitor Audio Gold 100 speakers.  I am looking for a high quality software to replace iTunes. I must to able to easy transfer existing files to the new software. Any suggestion would be appreciated.