Origin: Bree and Susan were good friends and neighbours for many years on Wisteria Lane.
Since Then: The two stayed good friends. They told each other secrets, they gossiped, played poker etc... They also both helped each other through some hard times, such as when Rex died, Susan attended his funeral and she comforted him. Bree also helped Susan through many hard time as well, such as when Susan was put on dialysis; Bree made it her mission to find her a kidney donor, and then chose herself to be the donor as she needed to do something to feel meaningful.
Origin: Susan found out Edie was having an affair and then Edie tried to warn Susan that Karl was having an affair.
Prize: For Susan; Mike Delfino, compensation for her house burning down, pride, a more quiet street. For Edie; Mike Delfino, Karl Meyer, compensation for her house burning down, pride, to ruin the Susan.
Fuel: Susan and Edie were originally friends, but later turned against each other after Susan insulted Edie for sleeping with a neighbor's husband. In Season 1, Edie and Susan saw and fought over Mike Delfino, a plumber who just moved onto Wisteria Lane. Soon in the season, Susan breaks into Edie's house with the pretense of borrowing flour when she thinks Edie is having sex with Mike. Accidentally knocking over a candle and setting the house on fire, Susan escapes the house, just to discover that Mike wasn't the man plowing Edie. After being blackmailed by Martha Huber, who thought Susan wanted to kill Edie, Susan steals and destroys her measuring cup, which she left behind at the burning house. After Martha's death, a guilty-feeling Susan rows to the middle of a pond with Edie, where she confesses to accidentally burning her house down. After reacting by throwing Martha's ashes into Susan's face, Edie and Susan reconcile at Susan's house, during which Edie hoses Susan down to get Martha's remains off so her ashes can be spread on the Lane. Edie uses Susan's guilt to get her to join the Ladie's poker night. In season two, Edie starts a relationship with Karl Meyer, Susan's ex-husband. AFter hiring a detective to spy on Karl, he thinks that Karl is cheating on Edie with Susan. Susan, thinking it was the end of her "friendship" with Edie, sends Edie a letter confessing everything. After the detective is paid off, Susan attempts and fails to steal the letter back. When Edie reads the letter, she retaliates by burning Susan's house down. After discovering who burns the house down, Susan get's Edie's confession to the crime on tape via wire. Edie discover's this betrayal, and chases Susan to try to get the tape, during which she gets stung by yellow-jackets and having her hospitalized. Feeling guilty, Susan forgives Edie for burning her house down, and promises to not turn the confession tape over to the police. In season three, Edie is present when Mike awakens from his coma (having snuck a peek at Mike's large penis just moment before, commenting "damn, and that's while in the coma") and discovers that Mike has suffered memory loss. She takes advantage by saying that Susan was cruel to Mike. After Susan discovers Edie and Mike having sex, Susan vows revenge on Edie. When Mike regains most of his memory, he realizes that Edie took advantage and breaks up with her. They stop fighting over Mike after Susan marries him in the last episode of season three. In Season four, Susan is among the housewives who disowned, insulted, and banished Edie from Wisteria Lane. In Season Five, Susan and Edie ultimately reconcile and their hate dies down to a friendly rivalry. Edie dies after crashing her car into a pole and getting electrocuted. Susan holds her hand in her final moments. She helps spread Edie's ashes after they inform Travers, Edie's son, of her death.
Resolved: Yes. Edie and Susan reconcile in season five, and Susan hold's Edie's hand as she dies, then helps spread her ashes on Wisteria Lane just as Edie and Susan did for Martha Huber.
Origin: Susan and Gabrielle were good friends and neighbours for many years on Wisteria Lane.
Since Then: When they first met, Susan didn't like Gabrielle because of her attitude, but she eventually got to like her. The two stayed good friends. They told each other secrets, they gossiped, played poker etc... They also both helped each other through some hard times, such as when Susan was on dialysis, Gabrielle visited her and comforted her on multiple occasions. She even promised to look after Mike and MJ if something happened to her. Also, when Gabrielle lost Grace, Susan helped her too. However, they also went through some difficult times, such as when Gabrielle was having an affair with John, Susan was assumed to be the adulterer, when it wasn't. She then forced Gabrielle to stop the affair and tell John's mother the truth.
Origin: Lynette and Susan were good friends and neighbours for many years on Wisteria Lane.
Since Then: The two stayed good friends. They told each other secrets, they gossiped, played poker etc... Throughout the years, they have both helped each other out through hard situations, such as Lynette getting cancer, Susan needing to be on dialysis until she finds a kidney donor, when Julie was attacked etc... However, Lynette has also kept secrets from Susan, such as, when Julie was attacked, she was pregnant, and only Lynette knew. This put a strain on their friendship but they soon worked it all out.
Origin: Susan and Mary Alice were good friends and neighbours for many years on Wisteria Lane.
Since Then: Mary Alice and Susan were the first two main housewives to meet. When Susan moved onto the street, Mary Alice greeted her and helped her escape the moving truck she was locked in. As they got to know each other, they occasionally had poker games together with their other friends. They stayed good friends for many years and Mary Alice helped Susan cope when she was going through her divorce with Karl. When Mary Alice shot herself, Susan helped Bree, Gabrielle and Lynette to find out the reason why.