I've not seen anything after 2, DC, because Sky bought it from the BBC over here, and I don't have Sky. I keep meaning to buy the DVDs, but don't. I have season 3, and have had it for ages, but haven't started watching it yet.
In fact, there's a few shows I'd love to catch up on:
The Shield, which I haven't watched since season 2 either, and I've always wanted to get into
NYPD Blue but haven't had the chance. And with
The Sopranos coming up (I have a means of seeing them as they air in the US, I think, to save the wait), I'm going to be busy.