I love Dexter. I knew very little about it going in, and that's probably what hooked me. I love Michael C. Hall's portrayal, and the voice-over narration he provides. I find it fascinating to watch him playing "public" Dexter, while we hear the true "inner" Dexter speak to us. I like how the audience can see things about Dexter that perhaps the character himself doesn't want to admit about himself.
There are three levels to the character that are constantly in play, and Hall handles it beautifully. I enjoy the gruesome humor, the office politics, and the fact that a serial killer is also a "vigilante hero" of sorts.
The show certainly isn't perfect. Too much time is spent with characters like LaGuerta and Quinn, and I don't think they add much to the show. The "ghost" of Harry should have been phased out much sooner. But, I'm looking forward to seeing where the show goes next. Is the nanny going to be a major player? Who is the Colin Hanks character?
I think this show only had a one season left in it....two at the most. It should probably wrap up soon. I'm not sure how they could possibly end this and have it feel satisfactory...but I'm looking forward to seeing what they come up with.