Best way to connect a Sansa fuze (MP3 Player) to a hifi system for audio quality?

I have a sansa fuze and need to know the best way to connect it to my hifi system for the best audio quality. I was thinking of RCA, AUX or USB, all ports I have on my hifi but I am not sure which has best quality. Also, is lineout better or headphone out? I can use both. Which one will give me the best sounding audio? Thanks