I've won my Civ V game by using XCOM squads to take Venice.
I started the game with random civilization, random world type, and random world size. I ended up as America in a very large islandy world. I realized early on that my best chance for victory was by doing the mission to Alpha Centauri, so I focused on research as my top priority. I tried to avoid war, but my neighbors kept attacking me. Each time, I fended them off with my superior technology. I never went on the offense, but ended up being given several cities when my attackers sued for peace. As the end of the game (2050 AD) approached, I realized I was probably not going to finish the ship in time. Venice would likely win, with the highest score in the final year. Venice's score was so high because they had built so many wonders. Because it was all concentrated in one city, I realized my best shot at winning would be to take Venice for myself, get all the wonders, and get the high score. My massive tech advantage made it easy. XCOM squads are able to air drop anywhere on the map right after being built, so while I was building them, I sailed my carrier fleet over to Venice. Once the ships arrived, the squads dropped in, and the city was taken in only three turns. Then I just waited out the remaining years, and victory was mine!