Alright, old news for most I suppose (since it's actually three years old), but check out The Shield if you haven't already. In Norway it's been on Canal + earlier, and although my first thought was "ooh, another great series from the HBO network" it's actually from FX (don't ask me :p). Anyways, it's totally mindboggling and awesome -- I know the phrase might be overused, but it's really a groundbreaking series in its true meaning. Anyways, just got to borrow Season One on DVD from a friend, and woah it's just SO good. Forget everything you thought you've seen about cop series on TV. Watch this one instead - you won't regret. Seriously.
NB: Not for those faint of heart. I guess.