Poll Suggestion: Favorite Serial Killer Series

Choosing between "Twin Peaks", "Dexter", "Hannibal" and "Sherlock" is quite hard. Heard a lot of good things about "Scream: The TV Series" and "Slasher" but haven't seen them yet (which is odd, since I'm a fan of slasher genre). Cautiously curious about "Bates Motel".  

FYC: 
"Scream Queens" (2015-2016)
"Metod" (2015)
"MosGaz" (2012)
"Konferentsiya manyakov" (2003)
"Freddy Nightmares" (1988-1990) (anthology series hosted by Freddy Krueger should count in my humble opinion)

Not sure whether "Arrow", "The X-Files" and "Gotham" would fit, but all of them have at least 15 prominent serial killers characters, each.