A few  weeks back Nintendo announced that they were bringing back 31 year-old NES with 30 pre-loaded games. Now Sega wants to get in on the action. The officially licensed mini-Mega Drive will sport 80 stored games and let you plug in your original cartridges. 


http://i.imgsafe.org/8a58090f58.png


The  new NES will be made by Nintendo, while the Sega will be manufacturer by AtGames.  At games has a reputation for producing horrible products. 


http://i.imgsafe.org/8ae6c82b47.jpg



The NES will have HDMI.   The mini-Mega Drive doesn’t support HDMI out, it's rumored to only support the  old composite outputs. 

So the way I see it the NES will be the way to go,  with better build quality and HDMI support you can't go wrong.   Now if they would make an exception and add Mario Kart I would be set.