A judge said smirking serial killer Joanna Dennehy found murder "more-ish" as he ordered her to spend the rest of her life in prison for her spree of violence.
The 31-year-old killer smiled, laughed and looked disinterested throughout most of her sentencing hearing at London's Old Bailey.
Mr Justice Spencer - who described her as "a cruel, calculating, selfish and manipulative serial killer" - said her three murders were so serious that they warranted a whole life tariff.
The judge revealed that Dennehy sent him a letter saying she was not sorry for the murders.
He added that she told a psychiatrist: "I killed to see how I would feel, to see if I was as cold as I thought I was, then it got more-ish."
As she was led from the dock, she remained passive and composed.
Dennehy, of Orton Goldhay, Peterborough, pleaded guilty at an earlier hearing to the murders of Lukasz Slaboszewski, 31, Kevin Lee, 48, and John Chapman, 56, in and around Peterborough over a 10-day period last March.
Police launched a nationwide hunt to find her after the bodies were discovered in remote ditches in Cambridgeshire but she went on to drive 140 miles to Hereford where she repeatedly stabbed two dog walkers.
Dennehy, who wore a pink Adidas vest top in the dock while flanked by 10 security guards and her three accomplices, has also admitted two counts of attempted murder and preventing the lawful and decent burial of her murder victims.
Mr Lee's wife Christina was in court along with their children Chiara, 25, and Dino, 15, and about 20 other family members in a show of solidarity.
Afterwards they said in a statement: "We feel Joanne Dennehy brainwashed Kevin, causing him to make a bad decision, and he has paid for that with his life."
Retired firefighter Robin Bereza, who also attended the hearing, was one of the men who survived the Hereford attacks.
He described Dennehy as "evil" and said the ordeal had a lasting impact on him,
"I'm not as confident as I used to be - I'm quieter and not my normal self," the 64-year-old said.
Addressing Dennehy, who has been diagnosed with various psychopathic disorders, Mr Justice Spencer said she killed in "cold blood".
"Although you pleaded guilty, you've made it quite clear you have no remorse," he said.
"Only a matter of days later, you attempted to kill two more men - victims chosen entirely at random.
"Miraculously, they survived.
"You claim to feel remorse for those attacks but I have no hesitation in rejecting that."
Gary Stretch, 47, of Riseholme, Orton Goldhay, Peterborough, thought to be Britain's tallest serving prisoner at 7ft 3ins, was found guilty of the attempted murder of Mr Bereza and John Rogers after helping Dennehy select her victims in Hereford.
He was also convicted of three counts of preventing the lawful burial of a body at the trial at Cambridge Crown Court.
Representing him, Karim Khalil QC said: "There is no proper evidence that, in spite of knowing what she had done, he derived any pleasure from it."
But the judge said he had knowingly played his part in the misery caused by Dennehy.
Stretch yawned loudly as he was told to stand for sentencing.
The judge ordered him to serve life in prison, with a minimum term of 19 years.
Nigel Lickley QC, representing Dennehy, who the court heard was called Joanne at birth, said she had not intended to "embarrass or humiliate" her victims.
"In essence, the crimes are aggravated by the number of offences and the attempted murders," he said.
The trial of her accomplices, Stretch and Leslie Layton, at Cambridge Crown Court earlier this year, heard that Dennehy "cast a spell" over some of her victims.
Dennehy met Mr Slaboszewski just days before his killing at a property in Peterborough on or soon after March 19.
He told friends he had met an "English girlfriend" and it is thought he went to meet Dennehy expecting sex.
She stabbed him in the heart and stored his body in a wheelie bin - at one point smirking as she showed the corpse to a teenage girl.
In a statement issued after today's hearing, Mr Slaboszewski's family said: "The sad news about Lukasz's death shocked us all as no one had ever thought that such a tragic event would happen to our family."
On March 29, Dennehy went on to stab Mr Chapman at the block of bedsits they shared in Bifield, near Peterborough.
The court heard Mr Chapman, a Falklands War veteran, had been scared of Dennehy and described her to friends as the "man-woman" because of her intimidating nature.
Afterwards Dennehy contacted Stretch and told him: "Oops, I've done it again."
She then arranged to meet Mr Lee - her landlord with whom she was having an affair - before stabbing him to death.
Dennehy was likened to "Uma Thurman from Kill Bill and the woman from the Terminator" by married father-of-two Mr Lee shortly before the frenzied killing.
With the help of Stretch and Layton, she transported the bodies in a car registered in the false company name Undertakers and Sons.
Mr Lee's body - wearing a black sequin dress and arranged in a sexual pose in a "final act of humiliation" - was discovered in a ditch near Newborough on March 30.
On April 3, the bodies of Mr Slaboszewski and Mr Chapman were found in a ditch at Thorney Dyke.
As police launched a triple murder investigation and appealed for information about their whereabouts, Dennehy and Stretch travelled to Hereford after she told him "I want to have my fun".
Once in Hereford, the two of them randomly selected Mr Bereza and Mr Rogers. She repeatedly stabbed them while Stretch watched and waited.
Layton, 36, of Bifield, Orton Goldhay, was found guilty of preventing the lawful burial of two murder victims and perverting the course of justice.
Mr Justice Spencer said he had played a "subordinate role" to Dennehy and Stretch.
The judge ordered that he serve a total of 14 years in prison.
A third man, Robert Moore, 56, of Belvoir Way, Peterborough, pleaded guilty to assisting an offender.
Moore was sentenced to three years, after the court heard it had taken "courage" for him to admit his role in providing accommodation to the killer for two nights.