There are a lot of emulators that you can try out on your jailbroken iPhone. However, most people don’t know how to transfer ROMs to iPhone.
Here is my post about file transfer and here are the locations for various emulators.
- NES: /var/mobile/Media/ROMs/NES/
- mame4iphone: /var/mobile/Media/ROMs/MAME/
- genesis4iphone: /var/mobile/Media/ROMs/GENESIS/
- gpSPhone: /var/mobile/Media/ROMs/GBA/
- psx4iphone: /var/mobile/Media/ROMs/PSX/
Note that I don’t know WHERE you can get the ROMs, so don’t ask me.