As a passionate fan of Borussia Dortmund I have a little bit of a weak spot for soccer data. I constantly find myself clicking through wikipedia or the german soccer data site transfermarkt. Last month a user on kaggle uploaded an unbelievable huge soccer database. You can find it here.
The kaggle community already jumped on this dataset and created some very interesting analyses. For example, are you interested in the different stats of the top 20 players? Or how the players moved between the leagues? You can also learn about the predictability of the different leagues.