Nonhosonno (Sleepless) (2001)

Argento's last truly watchable film, received with audible sighs of relief after the appalling Phantom of the Opera remake that preceded it, this is a return to the pure giallo format in which he excelled between 1970's Bird With the Crystal Plumage and 1975's Deep Red. The film was deliberately conceived as an attempt to recreate the ambiance of those earlier works, and the usual excellent use of Turin backdrops and an effective Goblin score add to the celebratory mood.
Its only concession to the new century, and a regrettable one I fear, is the greater excessiveness of its set piece violence. These moments which once seemed daringly unusual are now merely a tedious convention, and counterproductive with it, spoiling rather than enhancing the tension of the rest of the film, and alienating in their artificiality as much as their sadism. 
The twist ending may be a tad more predictable than in his true golden age, and perhaps the juvenile casting feels a little lightweight in comparison, but overall this is decent work, with predictably sterling contributions from Max von Sydow and Gabrielle Lavia, and a beautiful heroine in Chiara Caselli (from Antonioni's Beyond the Clouds).