Whom do you root for, the cops or the criminals? It's hard enough choosing between the flawed fuzz and the slick dope slingers in writer David Simon's current gritty HBO crime drama, ''The Wire.'' But in the gripping six-parter The Corner, cowritten and exec-produced by Simon, heroes are even hazier. Set (like ''The Wire'') in drug-blighted Baltimore, ''The Corner'' forgoes the badges to focus on the baddies, the most frustratingly sympathetic family of addicts and petty hustlers ever to shoot up on screen. And it's all based on a true story. EXTRAS Sadly, DVD viewers get only bare-bones cast and crew bios, plus unnecessary ''Next On'' teasers with this two-disc set.