I am "seriously" impressed with Channel Ten's new police action/drama Rush. The premise is fun (and makes for lots of good action), the writing is good, the storylines are interesting (yes, I know, we're only two shows in but it looks good nonetheless), the characters are interesting, the cast is excellent (plus Claire van der Boom is gorgeous), and the production is fantastic (I love the immersion that handheld camera work gives viewers).
The best part: all of the show's episodes are online along with a bunch of other behind-the-scene videos -- that too for free! Channel Ten really kicks ass for doing this for so many of its biggest shows.
And speaking of good cop shows, I also like Channel 7's City Homicide but its broadcast timing is such that I haven't watch more than a few episodes of it. I guess I'll have to wait till it comes out on DVD.