It's a confusing world out there -- as epitomized by this week's DVD releases. First up is 'The Girl With the Dragon Tattoo,' an anything-but-straight-ahead mystery thriller about he unlikely teaming of a journalist and a female computer hacker who investigate a 40-year-old crime. Then there's the angst of 'A Single Man,' about a college professor who has to navigate a post-relationship life in 1960s Los Angeles. And, finally, there's 'Brooklyn's Finest,' about three dysfunctional cops trying to survive one week on the mean streets of New York. Read on.