I would first do the Great Ocean Road. Head towards Geelong, and then to Torquay. Stick the coast road after that, being sure to check out Bells Beach (One of Australia's most famous surf beaches) along the way. You will eventually come to Apollo bay, a good place to chill out for a bit, very laid back. Keep going until you hit Warrnambool, checking out The Twelve Apostles (just before Port Campbell) on the way, then if National parks are your thing, head up to The Grampians National Park.
Then you could head East towards Bendigo, and then towards Wangaratta. Head through the mountains to Dinner Plain, Omeo and Swifts Creek along the Great Alpine Road, then down to Bairnsdale.
Then head back to Melbourne via the coast roads - through Sale, Woodside, Leongatha (you could take a side trip to Phillip Island here if you wanted to), Inverloch and then up the edge of Port Phillip Bay.
I have done this route before, and it was great - You get to see a lot of different country and its a good way to experience Victoria.
Best of luck with it, I hope your road trip is awesome! almost 9 years ago
Mornington Peninsula Freeway, Mt Martha to Sorrento then across to Flinders on way to Hastings via Arthur's Seat, Red Hill on to Bass Hwy and down to Phillip Island. Take your time; plenty to see.
Or, stop at Sorrento, catch ferry to Queenscliff and drive down The Great Ocean Road to Port Campbell (very nice Pub there.).
Vaya con dios! about 7 years ago