If you guys liked this then you MUST watch The shield.
one of the best and most brutal shows on TV.
I watched Season 1. It's quite good, really.
I've seen many similarities with The Wire (the ambitious captain, the lack of police resources, the corrupt chiefs, the bastard bad cop, ...) but it only deals with the cops' side. You only see the relationships between the gangs through the effect it has on cops (Los Mags, the Toros, Rondell), same for the drug addicts (the hooker, forgot her name).
It's still a very neat show but The Wire has a more complete look of things, from every possible angle.
Also, The Wire is more focused on a long and difficult investigation whereas The Shield is more about everyday police work, with a couple of investigations here and there, but they're solved quite quickly in comparison.
That said, I haven't started Season 2 yet, so it might get (even) better soon.