First of all, the best thing about Inception is the fact that it is a truly original idea. And - to give a somewhat-recent example - unlike Avatar, which had interesting creatures that interacted with their environment in very unrealistic ways, Inception is a well-thought-out, original idea. It's also not an adaptation based on a book or a comic or an old television series or a line of toys. It's not a sequel or a prequel or a reboot or re-imagining of some previously created work.