Game Boy/Advance/Emulators

NES

• PocketNES - This is probably the most well known and highly regarded NES emu for the GBA and with good reason. No FDS support, the lack of a few (relatively unused) mappers and the unusual scaling mode (affects text in some RPGS but is better overall) are probably the biggest detractors. This modded version is produced by dwedit and has cheats and a few more mappers and tricks.
• HVCA/(formerly) Famicom Advanced - In the land of GBA code nes emulators pocketnes is king, lets just say this is a major threat to that position. FDS support (with diskrom.sys file) and in some respects a nicer scaling mode as well as more mappers than pocketnes makes for a damn fine emulator.