This is a good one and often encountered. Hitler invented the autobahn, the "interstate highway." Therefore interstate highways are evil.

A very common fallacy. A genetic fallacy justifies an argument based on its origin, or the character supporting it. For example, many dismiss policies that were promoted by the Nazi party as inherently evil offhand without justifying why the action itself was evil. Instead of focusing in on the act itself, they will berate the character of the subject sponsoring the idea or policy. That gets us off the point at the end of the day and isn't very effective at all.

Cheney was the CEO of Halliburton!! Halliburton!! No bid contracts to Halliburton!! Did I mention Cheney worked at Halliburton?

Added this one to cover some recent nonsense about FDR: for example, FDR was a socialist, and this is bad, therefore his programs (such as Social Security) are bad! By the same reasoning the Volkswagen is a bad car because Hitler initiated the company that made the car.