Hayley's first appearance on the Street
Hayley made her first appearance in 1998, working alongside Curly Watts and Alma Baldwin in Firman's Freezers.
Julie describes her character as "quite a nervous little soul" in those early days, but insists: "She's got a bit more strength in her since then."
Hayley admits to Roy that she is transgendered
"I think this is Hayley's iconic scene of her time in Weatherfield," said Julie.
"The issue is quite outdated now really, but at the time it was a massive deal for Coronation Street to take on this issue and it was really important to me to do it with respect for the people that I was representing, people who were going through this in real life.
"It was one of my proudest moment in my time here where we got mentioned in Parliament as being really instrumental in changing people's attitudes towards transgender people in this country and I think that will be one of the proudest moments of my life.
Roy goes to find Hayley in Amsterdam
After going to Amsterdam to declare his love for Hayley, Roy is dismayed when she rejected him because she felt he couldn't cope with the fact she is transgendered.
But at the last moment Hayley arrives at the airport to tell Roy, in quite an unusual way, that she will be coming back to Weatherfield with him.
Julie said: "This was one of our best times on Coronation Street."
The first kiss
Roy and Hayley would soon become the iconic couple of Coronation Street, and this is the first moment they kissed.
"This is one of my favourite scenes ever," said Julie. "I just think it was a beautifully written scene, it was really simply shot and I think it was a little bit of Roy and Hayley magic.
Roy and Hayley's first wedding
In 1999, Roy and Hayley decided to declare their love to one another in a blessing. But when Les Battersby tipped off the local press, they were forced to cancel the wedding and have their ceremony in the back room of Roy's Rolls instead.
Hayley slaps Tracy
In 2003, the Croppers fall foul of scheming Tracy Barlow, as she takes a bet that she can get the most faithful man on the street into bed - Roy. Drugging him and taking him home, Tracy hatched an elaborate scam to extort money, lying that she was carrying Roy's child.
An angry Hayley arrives at Tracy's door to confront her about the situation and gets so angry with her; she gives her a slap to the face.
"This is the only bit of violence you ever see Hayley inflict on anyone," said Julie. "That's how bad Tracey is, she even made Hayley slap her!"
The Croppers become parents
Hayley and Roy paid Tracy £25,000 and were overjoyed to become parents to baby Patience. But when Tracy let slip that the real father is Steve McDonald at his wedding to Karen, the heartbroken Croppers gave the baby back.
"We had some lovely times filming these scenes," said Julie.
"I've always loved working with the babies on set."
Hayley opens up to Becky
Hayley and Becky would become firm friends on Coronation Street and this is the moment Hayley opens up about her past as a man.
The actress said: "It gave me the chance to do some wonderful scenes with Katherine Kelly; I loved every minute working with her as Hayley and Becky."
Hayley makes Maria see sense
In 2010 Hayley found herself in hot water with local bad guy Tony Gordon, as he tied her up in Underworld to get revenge on Roy for sending him to prison.
In this scene, a frantic Hayley is trying to make Maria see that Tony is not the man she thinks he is.
"I loved the Tony Gordon storyline," said Julie.
"I love all the episodes where we were having the siege in the factory and I was tied to the chair and guns were being wielded - I never get a chance to do any of that action stuff so it was really, really exciting."
Roy and Hayley's second wedding
On 30 August 2010, Roy and Hayley were finally able to legally go up the aisle.
After a number of glitches (including a derailed carriage carrying the bride and bridesmaids, Becky and Fiz) the Croppers officially declared their love for one another.
Julie said: "I think everybody remembers the ace scenes with the steam trains and Hayley, Fiz and Becky having to go on the pump train down the track to get to the church on time after Mary had sabotaged the wedding.
"These episodes were absolutely beautiful."