The Texas Sharpshooter
The Fallacy
Cherry-picking data clusters to suit an argument, or finding a pattern to fit a presumption.
Why it's wrong
This 'false cause' fallacy is coined after a marksman shooting randomly at barns and then painting bullseye targets around the spot where the most bullet holes appear, making it appear as if he's a really good shot. Clusters naturally appear by chance, but don't necessarily indicate that there is a causal relationship.
Example
The makers of Sugarette Candy Drinks point to research showing that of the five countries where Sugarette drinks sell the most units, three of them are in the top ten healthiest countries on Earth, therefore Sugarette drinks are healthy.