Like everyone else, my dream viv would be an entire room.
The walls and ceiling would be painted to resemble an Australian landscape. A rustic looking wooden playhouse would be cut in half and affixed to look like it was coming out of the mural and then wooden fence posts would surround it. Since beardie's often climb and lounge on fence posts in Australia I thought this would be a nice touch.
Near the house and fence posts a garden of fresh greens and herbs would be planted in individual containers sunk into the floor. This would provide a 24/7 food source in addition to other veggies, fruits and insects. A shallow pond sunk into the floor would gradually go from being level with the floor to 4 - 6 inches in depth. Rocks and logs would be strategically placed in and around it creating a safe place to paddle, lounge or play.
Four Mega-Ray heat/UV bulbs would be placed throughout the room to provide basking spots at multiple temperatures and heights. In addition to the Mega-Ray's the room would be lit by a number of fluorescent lighting bulbs and a bay window of natural light. The lights would be set to come on and go off in a staggered fashion over the course of an hour at the beginning and end of each day in order to cycle through like the sun.
A de/humidifier would consistently keep the humidity at around 50% and the room would be equipped with its own thermostat. Some sort of air-exchange fan would constantly be circulating fresh air into and out of the room. The access door would be glass french doors that you could observe them through as well as to make sure no one gets toes or tails pinched when the door opens and closes.
The room would, of course, come equipped with a large walk-in closet which would contain a fridge for beardie salad, feeder racks for storing worms and roaches, a large sink and stainless steel work-surface, grow racks for replacement herbs and greens and all manner of extra supplies.