Heroes and Battlestar Galactica) is the frankly adult tone of the series: The violence is plentiful and occasionally graphic, and there are frequent bedroom couplings between the team members and supporting players. There's also a maturity to the relationships that exceeds the usual scope of sci-fi, most notably in the affecting "Captain Jack Harkness," which sends him back to the London Blitz, where he meets and falls in love with a handsome American pilot who happens to share his name. Their love affair, like the majority of Torchwood's "grown-up" storylines, is handled with taste and real emotion. Extras on the First Series are remarkably plentiful; six of the seven discs include entirely new behind-the-scenes featurettes that explore the main characters and their major story arcs, location shooting, the impressive SUV that the team drives, and the show's extensive special effects and alien creations. Barrowman also contributes a very funny "Captain's Log," which invites viewers to join him on one of the final shooting days of the series. The entire seventh disc is given over to Torchwood Declassified, the 13-part program which explored each episode on BBC Three and the BBC's Torchwood website. Commentaries are offered for all 13 episodes, with Davies, Barrowman, Myles, Burn Gorman (who plays Torchwood's medical officer, Owen Harper), David-Lloyd, producers Richard Stokes and Julie Gardner, and various episode writers, directors, and producers all lending their voices. A small battery of deleted scenes and outtakes, as well as previews for DVD releases of other BBC programs, including Doctor Who and MI-5, round out this impressive set. --Paul Gaita

Stills from Torchwood (click for larger image)