SMPlayer. In my usage it was less resource intensive than vlc.
You would notice the difference clearly on less powerful hardware. Vlc struggled to play 1080p x265 mp4 file, but SMPlayer played it without any hiccups.
Also it remembers the last playing position of files and subtitles loaded last time, search & download subtitles, save screenshot, play youtube or any streaming link, play dvd, play internet radio, save playlist, all other basic player features.