I only have 1 beardie, so I use premium reptile turf by Petscape products. Its really high quality and comes in 18" wide to fit the tank. It also washes and wears extremely well. You can see pics of it at my Dragons album at Fotki. Link is on homepage if interested.
http://www.geocities.com/ahr0803/dragon.html
However, If i had more than one dragon I would go with the double sifted washed playsand ,also. For dragons under 10" tip to tail I prefer using paper towels.