6. Hannah McKay
Now I dont know about the rest of Dexters fans, but I was pretty disappointed when the fascinating big bad Issak Serko was written out to make way for the inconsistent (but still marginally unique) arc involving Hannah. Nonetheless, I ran with it and, although Id hoped for a more exciting conclusion to the season, she did give us some unique new circumstances. For one she put a particularly intriguing wedge between Dexter and Deb. I found it highly entertaining to see Dexter grapple between his perceived love of Hannah and his concern for his sister. And with the tension between the two sure to be higher than ever in season eight, wouldnt her return make a really great way to wrench up the tension? So far it's all but confirmed that Hannah won't be making a return. Obviously the writers don't agree.