What game systems are easy to emulate?

Game systems that are easy to emulate typically include older consoles like the NES, SNES, Sega Genesis, and Game Boy. These systems often have simpler hardware architectures, making it easier to replicate their functionality in software. Additionally, their extensive documentation and active development communities contribute to the availability of stable emulators. More recent consoles, such as the PlayStation 2 or Nintendo Wii, can be more challenging due to their complex hardware and proprietary technologies.