Personally I've always preferred mplayer's no-nonsense interface. That's been the biggest thing that has kept me an mplayer user for several years now. VLC als

Personally I've always preferred mplayer's no-nonsense interface. That's been the biggest thing that has kept me an mplayer user for several years now. VLC also seems to mandate a larger performance hit while playing a video, no matter what. For the most part, VLC and mplayer provide a similar experience, and both tools have major dependencies on ffmpeg. It's just a matter of preference on the interface, and if you utilize any of VLC's niceties that justify its performance decrease (I've heard this happens because VLC forces software processing of the image at some stage to facilitate easy application of filters, and mplayer (and its descendants) doesn't. I don't know if this is true or not).