What I Would Do If I Were The Last Man On Earth
1. Hopefully, some women would still be there.
2. Find them, so mankind does not have to die out.
Would the consequences of inbreeding and drifting be deadly after a few generations, or would the genetics even out?
3. Move to a nice house in a warmer climate
4. Find a way to generate some electricity
All power plants will probably shut down in a catastrophe that wipes out almost all of humanity.
5. Consider how things can go on
6. I keep wondering about my outrageous luck...
7. Learn about some technologies that could be made to work again
8. The Norwegian writer Jostein Gaarder described this scenario very interestingly as a draft novel in "The Ringmaster's Daughter".