I would likely find an intact machine shop, with all the tools I need to make anything I want, I would procure every generator I could find, hoard canned and or non-perishable goods, and spend the rest of my life or at least untill I got bored, building the many things I've designed, and perfecting them... I've got an entire world's worth of parts and materials laying about, and just using up the resources of one city would take me a long time, also hunting with military grade arsenal is always fun... hey look a deer, let's hit it with some HE tank ammo... hehe... I would probably be building/blowing shit up for quite some time before I either died of old age/disease/injury or succumbed to the self destructive side of my insanity due to sheer loneliness.
That, or my mind would snap, and I would just blow myself up with a big pile of C4 or something.