We've seen the richest person in every American state, and now Frivilligt from Reddit brings us the richest person in each European country:
The big difference between the US and Europe is that Europe doesn't have the technology barons and oil tycoons who often pop up in the ranks of American billionaires. Instead it's mostly about retail chains and finance, along with the fact that Nutella is perhaps a more lucrative business than one would have guessed.
Update: Unfortunately, it is difficult to assemble unequivocally correct information about ultra high net worth individuals (see my interview with Thomas Piketty for more on this) so some of these entries are contested. According to this Norwegian magazine ranking, for example, the richest Norwegians are John Fredrikson (who's since left the country) and Olav Thon with Stein Erik Hagen ranked way down at number 7.