mpv is really good but a little light on the GUI; I recommend VLC for most people

SMPplayer is a frontend for mpv which I use and like.

Yep, highly recommend https://www.smplayer.info with dark skin :)

It also has MPC GUI mode for nostalgia :)

On macOS, IINA is my go-to mpv wrapper nowadays, and last time I tried, Haruna is pretty good on KDE.

mpv is super for lower spec hardware!

mpv is great for scripting, though.