Remember when serial killers weren't part of your daily prime time and movie diet? No? These days, one murder is never enough — we want antagonists that kill and kill again, preferably creatively. The latest addition to the psycho roster is the murderous couple at the heart of “Wicked City,” which debuts Oct. 27. While it remains to be seen whether Ed Westwick and Erika Christensen stick with us (the show had just 8 percent viewer awareness when Research firm Ipsos MediaCT surveyed viewers in September), that doesn't leave us lacking for indelible serial killers. Here's a list of 17 that could have been much longer, but it started to freak me out.