There have been a countless number of serial killers throughout history, and certainly more prolific ones, but the timing, circumstances, and unsolved nature of the case continue to make Jack the Ripper the most famous serial killer in history. The murders came at a time when media coverage could be both more acute and more widespread, and it allowed the public a closer look into how police agencies operated at the time, exposing both their strengths and shortcomings. Of course, the lack of modern forensics hamstrung the investigators in the late 19th century, and while the police file for the case was extensive and active for several years, much of the evidence disappeared from the file without explanation, possibly as souvenirs.
In many respects, the pattern of crime and writing letters was not novel at all. Around the same time the Zodiac Killer was murdering people on the West Coast, the Son of Sam terrorized New York City in much the same way by killing at random and writing letters to the police. Serial killers often use a set pattern and/or rituals as part of their modus operandi, so in that regard the actions of the Zodiac Killer didn't exactly distinguish him from other serial killers.
The main difference, of course, is that most serial killers are caught, including the Son of Sam (David Berkowitz), while the Zodiac Killer's identity remains an unsolved mystery. By both remaining unidentified and leaving seemingly tantalizing clues in his writing, the Zodiac Killer ensured his notorious legacy in American history, much the same way the attempt to identify Jack the Ripper continues to fascinate people across the world today.
For most people, Ted Bundy is the quintessential serial killer - a good-looking, highly intelligent man who used his charm to lure an untold number of women to their deaths. In fact, as the judge announced his death sentence, he noted Bundy's intellect.
