An Atari 2600 Native emulator would rock. That was the very first system I was exposed to when I was a kid. Pitfall, Grand Prix, Yar's Revenge, Berzerker....good times!
I guess you can play some of the same titles on the Atari 800, 5200 and 7800 emulators, but for some reason it's just not the same. Those games had a particular sound that those other emulators can't recreate.
I know people out there have the skills to create a 2600 emulator, especially with all the incredible emulators they've created for the Dingoo in the past couple of years (even more impressive in the last few months).
I wonder if there's something difficult or impossible to emulate in the 2600 that makes in unavailable?