Here are some of the best PSP emulators available, particularly for Android devices:

• PPSSPP: Widely regarded as the best PSP emulator, PPSSPP is praised for its ease of use, compatibility, and performance. It is available for free with an ad-supported version, and a paid version is available for $4.99 to remove ads. PPSSPP is open-source and frequently updated, making it a popular choice among users.

• RetroArch: This emulator is unique because it can emulate multiple gaming systems through the use of plugins. It is free and open-source, but it has a steeper learning curve due to its complex setup. Despite occasional compatibility issues, it is a versatile option for users interested in emulating more than just PSP games.

• Lemuroid: Another open-source emulator, Lemuroid supports various consoles, including the PSP. It offers features like auto-save, ROM scanning, fast-forward support, and cloud syncing. While it has a learning curve similar to RetroArch, it is a strong competitor in terms of performance and compatibility.

• Rocket PSP Emulator: This is a relatively new emulator that uses the PPSSPP open-source project. It offers features like save and load states and a software controller. Although it is not as mature as PPSSPP, it is a free option worth considering if other emulators do not meet your needs.

Overall, PPSSPP is generally considered the best option due to its ease of setup, robust support, and high compatibility with PSP games.