Why not VLC? I suppose mplayer and its forks are good for cross platform. On Windows, and if you ask me, the best experience i have now is MPC-BE. Which is based on MPC-HC, which is based on MPC.
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).