First place with every guided city tour is the great Saint Georges Church, one of the most beautiful gothic churches in southern Germany with a romantic door portal:
Kirche St. Georg

House of history in Dinkelsbuehl:
Haus der Geschichte - von Krieg und Frieden

Kinderzeche Dinkelsbuehl - a festival about children, homeland, dancing, funfair and games:
Kinderzeche

Museum of the third dimension - unique with its interactive elements to show people techniques, used since medieval times to giving depth to rooms and halls:
3D-Museum
 
The 2012 built Limeseum located at Ruffenhofen is the first new museum in Bavaria after beeing declared World Heritage Site of UNESCO. Wander around on roman tracks and discover their history:
Limesmuseum