EmuNations

BGB is a Gameboy emulator which lets you run Gameboy and Gameboy Color games. It has excellent accuracy, gamepad support, high quality sound and graphics, smooth V-sync animation, and low latency...

Mesen is a multi-system emulator (NES, SNES, Game Boy and PC Engine) for Windows & Linux built in C++ and C#. It focuses on accuracy, though does incorporate graphic mappers and filters (i.e. HD packs in HDNes format as well). It also allows video recording...

No$GBA is currently the fastest working GBA emulator, though not the most accurate on GBA and even less on DS. It supports multiplayer and is able to load multiple GBA/NDS ROM files for linking games...