I have to say, this was one of my best road trips ever: fabulous landscapes, iconic beaches, amazing wildlife (lots of koalas in the wild!) and national parks, great bushwalking, good surf (not so much my cup of tea but husband raved about the waves, we even stopped at the World Surfing Museum in Torquay, definitely worth a visit), and really good food too, from hole-in-the-wall fresh fish eateries to more sophisticated gourmet spots such as Chris's Restaurant in the Otways.
If you can, try to spend a couple of days there, because there's a lot to do and a day trip won't give the Great Ocean Road justice... To plan your trip, check out the local Tourist Office website, lots of interesting info.
So tell me dear reader, have you already visited the Great Ocean Road? Which other road trips did you like best in Australia?