Akinator is a genie who asks you to think of a character, fictional or non-fictional, and tries to guess who you're thinking of via a series of questions. It's no great trick to program such a thing and Akinator clearly has a fairly large database covering even the most obscure of characters, but when he accurately guesses that you were thinking of Buster Bluth or even the protagonist of the latest indie game… there is briefly magic.
See if you can confound Akinator's knowledge at en.akinator.com. If you beat him you can add to his database too.