Blow up the NCR
In Fallout: New Vegas, there’s a few main factions you can side with. It’s meant to be looked at as the good, bad, and ugl.. I mean, and your own. The NCR is a faction that represents some sort of military organization, and its members are portrayed as the good guys, for the most part. Ceasar’s Legion is pretty much based on old Roman times, and they’re pretty evil.
In the DLC Lonesome Roads, you’re met with a question at the end. There’s some active nuclear missiles, and you have the choice of who you want to blow up. Now, of course you don’t blow up their actual headquarters, but you get to pick from to locations, each one representing either the NCR or the Legion.
It’s seen as morally wrong to blow up either, but blowing up the NCR is especially wrong in my eyes, as they’re only trying to restore some sort of law and order to the Wasteland. The Legion are downright bastards, so they might even deserve getting hit with a nuke.