Ticket to Ride, a casual board gaming juggernaut, is very light and cheery. Not at all the kind of thing you'd expect to be suited to a post-apocalyptic wasteland, but then, maybe that's why this works.
XsimonbelmontX made this last year for his wife's birthday, and it's incredible. He hasn't just reskinned an existing map/copy,he's designed an all-new map that visits each of New Vegas' major locations, as well as adding a new few new mechanics like roadblock tokens you can place on unclaimed routes (costing other players trains to break through them), a casino and perks.
He also went above and beyond with the board, token and box design.
You can see more pics here.