Adelaide was my favorite city in Australia. I'm easily biased by it's enormous, complex, varied, free public botanical gardens. Plus downtown there were glass elevators anyone could ride :D. (I am still a kid, I was happy on every elevator, escalator and slideway I got to ride the whole trip.) Only spent one day in Adelaide, arrived about 7:30 in the morning and left about 7:20 the next morning. The hostel was very kind, check in was supposed to be 2pm, but they let me check in at 8am and sleep a couple hours before exploring.