The PS2 is the best-selling console of all time, and for good reason. Released in 2000, it defined the 6th generation of consoles and brought the medium into the mainstream like never before. For me, it represents the golden age of retro gaming, a time when games were extremely ambitious, creative, and fun, and when the hardware finally allowed video game developers to bring all their ideas to life.
For years after its release, people fantasized about playing PS2 on the go in a handheld format. But from a technical standpoint, emulating PS2 is not easy, due mainly to its complex architecture and custom CPU/GPU. Only in the last few years have mobile processors become powerful enough to allow stable emulation for the vast majority of the PS2 library. Emulators have also come a long way thanks to the expertise of dedicated community developers, and updates to these emulators are still being released regularly, with major compatibility improvements year by year.
It's a dream come true to be able to have a "Handheld PS2", with full control schemes, additional buttons, high-resolution screens, and all the other benefits of modern tech. Not to mention that with many of the devices on this list, the original gaming experience can be improved upon thanks to resolution upscaling, faster loading times, HD texture packs, widescreen hacks, and much more.