Chucky? Pinhead? Jason Voorhees? Micheal Myers? Freddy Krueger? Leatherface? Notice the direction I'm going.
Chucky. He's a beast. He gave me nightmares back when I was a kid watching that shit. He seems like a funny killer too haha.
Hmm this is a toughie. I'd have to say it's the vag from the movie Teeth. D: Seriously though, I think I was most interested in Zodiac. Nobody was really that interesting to me other than him. Most of these other guys seem like mindless killers, who are almost immortal. Zodiac was a mortal human being, and yet he still killed and still fucked with the cops and dared them to try to catch him- which they didn't. It was so interesting and slightly entertaining in the way he messed around with the cops' heads, but still completely fucked up that everything was in real life.
Forgot about him but you're right he was a very fascinating character. *POTENTIAL SPOILER* Even at the end of the movie when he goes to look at the guy he thinks did it- while most or all of the circumstantial evidence fit perfectly with that guy's timeline they recently did forensics and none of it matched him. Fingerprints, DNA, nothing was a match with him even though everything else fits perfectly and logic tells you its him. Also like you said the fact that its a true story makes it that much more interesting. I asked my mom a bunch of questions about it because she grew up in SF/Bay Area and was a teenager during the time the Zodiac was on the loose. Really interesting stuff. Also reminds me also to mention the murderer from Se7en.
The guy from Se7en (shit, I can't think of his name right now) Do good guys count as murderers? Like..in revenge movies? Creasy from Man on Fire was so bad ass. Jigsaw Patrick Bateman Michael Meyers