One ring to rule them all... just kidding
I'd vote for Sergiev Posad (easy 1-1.5h trip from Moscow), Rostov ("Ivan Vasilievich Changes Profession" filming location) and Suzdal.

Balloon photo of Sergiev Posad (high-res and more photos inside):


«Сергиев Посад» на Яндекс.Фотках