Here's a question...
What two games would you put together to make an overall better game. So you'd be taking elements from one game and merging them with elements of another.
I was talking about this to my brother today. We agreed that a merger of Saint's Row 2 and GTA IV would be great. Take the fun and activities (soo many activities) of Saint's Row 2 and the realistic physics of GTA IV (Keep the Saint's Row driving control please) and in my mind, you'd have an amazing sandbox game! If you look deeper I'm sure there are holes, but just have fun with it.
(hah)
Go!