What good is sitting alone in your room when you could be watching Liza with a ''Z'', a just-restored song-and-dance spectacular, which shows two artists at their peak: Liza, looking stylish in Halston and sounding sensational (listen to her wail on ''God Bless the Child''), and director Bob Fosse, who blended Broadway panache (his choreography in ''Bye Bye Blackbird'' is wrist-popping, hip-rolling perfection) with a big-screen sensibility (using eight 16-mm cameras in lieu of de rigueur videotape).
EXTRAS A veritable Liza-palooza! Highlights: the S&M-ish ''Mein Herr'' (cut from the Cabaret medley); her '04 A&E Biography; and a giggly new commentary, in which the star admits to flubbing lyrics, admires her bust in a red minidress (''Thank you, Fosse!''), and dares us to learn the tongue-twisting title song. ''If you do, I'll send you those eyelashes.''