The Stadt- und Freiheitsmuseum Sinsheim is the town museum, set close to the old centre. Its strongest material looks at the 19th century: the revolutionary period around Friedrich Hecker and the waves of emigration that shaped this part of Baden.
It is a modest stop, but a useful one if you want Sinsheim to be more than the Technik Museum and the castle above town. Pair it with a walk through the Altstadt.