Australia's Answer to Alton Towers is Dreamworld, www.dreamworld.com.au.  This park boasts what used to be the World's tallest ride, the Tower Of Terror (now at number 4), which is a vertical reverse freefall rollercoaster drop from 393ft (120m).  On the same structure is what is still the worlds tallest freefall non-rollercoaster ride, The Giant Drop.  This is a ride where you get raised to the top of the tower in your seat and dropped to earth at a ridiculous 85mph experiencing 5 seconds of freefall!  The view from the top is amazing, you can see all over the Gold Coast.  The ride is so fast you don't hear anyone scream on the way down because basically they don't have time!  One of the best rides at Dreamworld is the Motocoaster.  Sitting in life size replica racing motorbikes, this is one of those high speed propulsion rides where you jet off from the start at the speed of light.  Crouched over your own bike, you really feel the part!  Adjoined to Dreamworld is White Water World, an amazing new waterpark with all hi-tech slides.  It has a Hydrocoaster which won best water ride in the world and you can see why.  Sitting in a large inflatable dinghy which can sit 3, you are shot around a rollercoaster track but propelled by water!  You even go up and down several big drops just like a normal rollercoaster.  How they propel the dinghy up and down the drops is anyone's guess but it is without doubt one of the best water rides you will ever go on.