I don't use Windows Media Player because the interface is waay too... simplistic... The GUI is supposedly user-friendly, but I just don't like it.
I haven't heard of those programs (J.River, xbmc, or media portal). Do they have a library interface similar to that of Winamp or iTunes? The essentials are music and videos with compatibility to flac and mkv files in addition to writing tags while in the library interface.
Could you give me a breif description of each program you mentioned?
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