PPSSPP is by far the best of the PSP emulators. Of all the emulators we tested, PPSSPP was the easiest to use, had the best compatibility, and the best performance. We wouldn't blame you if you thought we were advertising here but we're really not. PPSSPP gets frequent updates, has a paid version that removes ads, and it's the one that most other developers copycat from. We highly recommend that you try this one first.
CoolROM.com's game information and ROM (ISO) download page for Dead or Alive 2 (Japan) (Sony Playstation 2). Dead or Alive 2 is a fighting game. This game has been released in ISO and ROM formats. Dead or Alive 2 PS2 game developed by Team Ninja and published by Tecmo.
The ad-supported free version works fine if you want to test it out. The $5.99 price removes ads. The app is also open-source. PSPlay is one of the newer PSP emulators. It features a bunch of the usual stuff, including save and load states, hardware controller support, and network playing capabilities. It worked with all of the games we tried during our testing. However, there are far more games out there than we had time to test.
Thus, there may be the occasional game with lag or audio issues. Some Google Play reviewers have even found a few. Still, this is an above average emulator that is entirely free with no in-app purchases. There are ads, though. Also, it is based on PPSSPP's open source project. RetroArch is one of the more unique PSP emulators. Grundig satellit radio. It can actually emulate a ton of different gaming systems.
RetroArch uses the Libretro system. It essentially runs plugins that act as emulators. Thus, RetroArch can do anything from SNES to PSP as long as you have the required plugin. The emulator seems to work okay, but like most there are compatibility problems here and there.
There is also a learning curve since the system is rather complex. Even so, it's a good one to try out and it's completely free and open source. Rocket PSP Emulator is a very average emulator. It's relatively new, still has some bugs, and its compatibility is just okay. It uses the PPSSPP open source project so it has many of the same features. That includes save and load states, a software controller, and, again, decent compatibility.
We didn't have any overwhelming problems during our testing. However, you may want to try something a little more mature like PPSSPP itself. Still, in the event that it doesn't work for you, this is still an option.
It's completely free with advertising. There are a bunch of PSP emulators like this one. You can search Google Play for it and throw a rock and hit others like this. That doesn't make it bad, but it doesn't make it special either.