One model I had build before doing the Britannic and Olympic conversion sets was a small and simple model I had found on the internet was the DeLorean as seen in the movie Back to the Future part I.
It can be found here:
SF PaperCraftGallery
This website hosts 4 different kinds of this model depicting the DeLorean as seen in all 3 parts of the BttF trilogy
A larger, and more detailed model can be found on the paperinside.com website.
Here is a picture of my model
Next I am planning to build the Jurassic Park Explorer and the Ghostbusters Ecto1 wich can also be found on paperinside.com