I see there's already threads suggesting Texas and Arizona. But did you know there's actually a whole state squeezed between the two?
We've got some stuff to recommend us. The Rio Grande, which would probably attract settlements. Terrains varied from desert to desert scrub to forest to some decently tall mountains. Yes, the Rockies exist south of the Colorado state line.
There are two national labs, Sandia and Los Alamos, which, if they weren't hit, would be a good source of interesting tech and probably quest hooks. And there are plenty of mountains, and a good few lakes. And best of all, our water system isn't too far gone from what it originally was. And so long as you're near enough to a source of water for irrigation, it is possible to farm things here.
I'd like to think that we've got enough people living at least halfway off the grid for a respectable survivor community, so long as Albuquerque, Las Cruces, and Santa Fe all get hit. Otherwise, there would be large populations of soon-to-be dead folks leaving the cities for the rural areas that can't really support 1.5 million people without help. In that case, those few who were ruthless enough to survive would, at least, form the core of a decent bandit community.
I'd actually really like to see this. I can't think of any post-apocalyptic games that really went into New Mexico, so we're really underrepresented there. So, anyone for it?