Hey,
Since we're throwing random themes out there, and debate timelessness and this and that, the new Muppets movie is quite possibly the most entertaining movie I've seen in I can't remember how long. I'd be much more inclined to throw a huge sum of money in that direction as opposed to any of the suggestions tabled already. That and Stern has already dealt with Disney getting the license for Pirates of the Caribbean, which might make it a bit easier to do. Then again, the game won't live or die on theme alone. If it's a good game, people will play it regardless of theme, and there are TONS of examples of this.
Luke