There appears to be a complete lack of thread-action for this TV show. For those that haven't see it it's about a guy named Dexter Morgan who is a serial killer, not just a normal one, he only targets other killers to 'clean' the world. During the day he works as a blood spatter analyst for the Miami Police Deparment.
It's similar to 24 in a sense that each episode has suspense, action and the characters are well developed. Yet it's not got the same action, but still keeps you engaged. I'm suprised no-one's mentioned anything because it really is a fantastic show. Better than the current Prison Break, Heroes and probably lost - though I stopped watching that after season 2.
It's just about finished the third season in America and I think it's about to be shown on FX very soon in the UK. If you haven't watched it, watch it.