EmuNations

Ares was originally Near/Byuu's last project and was subsequently continued by new developers (including Luke from Cxbx-r). That said, it's an open-source, multi-system emulator focusing mainly on accuracy and some of its exhaustive features include but are not limited to native multi-platform UI adaptive sync, dynamic rate control, save states, run-ahead, rewind or fast-forward and much more..!

Visual Boy Advance - Merge (VBA-M) is a fork of the inactive open-source emulator Visual Boy Advance. It mainly targets Game Boy, Game Boy Color and the Game Boy Advance though somewhat offers emulation for Super Game Boy and Super Game Boy 2. While supporting all previous features, it adds Link-cable emulation between GBA gamepacks, Joylink GCN/GBA emulation, e-Reader(still in development), etc. It has a very good accuracy level and is available for Windows, Linux, macOS, BeOS, GameCube and Wii. 

SkyEmu is a low level GameBoy, GameBoy Color, Game Boy Advance and DS emulator. Its primary focus is to provide a good user experience through a good mixture of tradeoffs of accuracy, performance, features and usability...

• Highly accurate Game Boy Advanced emulation

• Game Boy and Game Boy Color Emulation

• Experimental Nintendo DS support (only capable of running homebrew currently)

• Cross Platform: Windows, MacOS, Linux, Web App (with touch screen controls for iOS and Android)

• Game Controller and Rumble Support with configureable keybinds

• 4x Save Slots with screenshot preview

• Game fastforward and rewind support (supporting very long rewind times)

• Support for emulating the Real Time Clock

• CPU, MMIO, and Memory Debuggers

• Dark and Light Themes

• Support for loading official BIOSs dumps