Game You Only Play Because of the Theme

So as I was playing #Star Wars Imperial Assault the other night and I got to thinking about how important Star Wars as a theme is to me.

It also made me realize that I probably wouldn't have picked up a game like IA if it had another theme (I know some people compare it to Descent).  So likely I would have never experienced or been drawn to a dungeon crawler if it hadn't been for the theme.

Anyone else have games they've only played because of the theme and may not otherwise have played it?