Handheld to play old genesis and nes games

[Handheld to play old genesis and nes games]

Smart phone

I've already considered a tablet but I'm not sure if it will give me a genuine experience. I played these games when they were new on the original systems so I won't be happy if the controls are off or the sound isn't right. It doesn't seem like the controls would be all that great on a tablet.

[Handheld to play old genesis and nes games]

I'm trying to give up my computer and I'd like a way to play these old games using a handheld. It would also come in handy at the library when I need a break from studying. Is there something on the market that can play both genesis and nes titles? I'd settle for one or the other if I had to.

 

Thanks