The reality bug - D.J MacHale

When Bobby Pendragon arrives on Veelox in hot pursuit of the evil Saint Dane, he discovers that the territory has achieved perfect harmony. All is peaceful on Veelox - because it's deserted! The inhabitants have discovered a way to enter their own personal dream worlds, where they can be whoever they want, whenever they want. Their bodies lie static while their minds escape to this dream realm.
Fresh from his "win" on First Earth, Bobby is confident that they can defeat whatever Saint Dane has planned. But once Bobby enters Veelox's virtual world - and sees his long-lost family - will he be able to resist the lure of the ultimate escape?