You'll want to browse the collections at Museum of Soviet Arcade Machines, Central Armed Forces Museum, and Rizhskaya Railway Museum. Some landmarks that you won't want to miss include Central Academic Theatre of the Russian Army, Ostankino Palace, and Arch of the Main Entrance of VDNH. You can watch performances at Satirikon Theatre, Helikon-Opera, and Moscow State Historical and Ethnographic Theater if you're interested in local theater.