simple64 (formely known as m64p) (mupen64plus + GLideN64 + a GUI) uses mupen64plus-gui, a brand new mupen64plus frontend written in Qt5. It supports all thing things you’d expect from a frontend (savestate management, pausing, screenshots, etc..). simple64 comes bundled with GLideN64 for the graphics plugin. It should give you the best out-of-the-box experience available for N64 gaming.
Support for homebrew ROM header - mupen64plus/mupen64plus-core#977