I lived there for 26 years, and I don't care for Sydney either. Melbourne is very trendy, all fashion and culture, so I don't like there much either, and Adelaide has the reputation of being the unofficial most boring city in the world. Don't get me wrong, Australia's the greatest place on Earth, but you might not get much from the places you are going. I lived in Brisbane for 5 years in my early twenties and I liked it, but not really sure if it suits tourists. Cairns is a great spot and you'll probably have the most fun there, it's a good spot for heading out to the Barrier Reef, there's plenty of short day trips you can take up to Cape Tribulation or the Atherton tablelands and see some rainforest, check out the Kuranda railway, it's a track that snakes it's way up the mountain to a little village that's worth a look. Cairns is also full of nightclubs that are full of horny backpacker chicks too.
