Ian David's Blue Murder is an Aussie television drama, made in the mid-90s, before the Sopranos (I point that out because I see parallels in the quality of the writing, and also in the writers' ability to interpret and recreate an underworld with its own internal logic and ethics). It's about organised crime and dirty cops, based on true events in Sydney.
Blue Murder is a masterpiece. The script is tight and cool and sophisticated. Keep your eyes out if you're trawling the DVD bins (or the online equivalent), I found it for under ten bucks at Mount Druitt Target. It's worth owning this series, you'll watch it more than once.