Mine is Strawberry since it has a ton of options and plays a ton of formats. It's also (distant) fork of Amarok 1.4 and integrates well with KDE Plasma. I'm curious what other people are using these days. What's your favorite player?
I am but a simple man. All my music is FLAC. It is arranged neatly in folders. I just want to select an album to play. I do not need album covers, playlists, search, streaming, tags, lyrics, analyzers, or scrobbling.
Sometimes I poke around Wikipedia and see what other artists collaborated with, influenced, or were influenced by artists I like, and buy their albums.