I love The Third Man. It's not only a thrilling cult classic with excellent international and popular Austrian actors but also a authentic portrait of life in Vienna after World War II.
The Third Man Movie tour was a fabulously entertaining and informative way to learn about 20th century Viennese history and a fun way to connect the best film scenes with the onsite locations. I discussed some historical details with my mum (she grew up during and after the war in Vienna) afterwards, and she confirmed them all.
You can do the tour without having watched the film though it's infinitely more amusing if you have watched it at least once.