I like my little Panda so much, so I feel it could be the best car in the world! :-)
It is small outside so I can park it, but big on the inside, I can sit in the back or front!, (its better than the model that replaced it in this respect), it looks different, it has true 4wd and a diff lock, but it still does 55mpg, it has great air con and simple controls, you sit high up and it is easy to get into and out of -and also it is quite rare. All of this I think it makes it the best car in the world :-)