NGP.emu
Features:
PSG Sound support (DAC will be added in an update)
English/Japanese game language switch support
Supports ROM-based games in .ngc, .ngp, and .npc formats, optionally in zip files
Flash memory and save state support, auto-save and ten manual slots for save states.
About Save Games:
A .ngf file is created for games with flash memory
Save states are named .0A.ngs for the auto-save slot, and .0X.ngs where X is the slot number for manual saves.
NGP-specific Options:
NGP Language: select between English or Japanese for multi-language games