These are the relationships Richard has with the other characters in the series.
Richard loves his son, mainly because he can relate to him in many ways. He often teaches him odd ways to deal with bullies, and treats him more as a brother or a close friend than a son. Despite his questionable parenting, he still clearly loves Gumball, and does hurt when Gumball insults him.
Richard cares greatly for Darwin. In "The Goons" he lets it slip that Darwin is apparently his favorite of his children. He then immediately tries to cover this up by saying he is simply his "favorite fish".
Richard loves Anais of course, but often butts heads with her intellect. On the advent of Anais attempting to be dumb for a day, she replaced Gumball from the dumb trio, thus becoming Richard's second favourite child. Despite Anais having to clear things up or voice her opinions Richard was willing to even get a job to help his "little girl".
Richard loves his wife, just as much as he fears her. He did not have much courage when they were younger so obviously Nicole pulled most of the moves. But he still loves his wife, mainly because she was one of the only people who approved of him. He even admits in "The Fury" that his wife could do better than him.
Obviously, Richard loves his mother very much. Though in "The Kiss" he and Nicole flee from her at first, in "The Man" he with his whole family celebrate her 63rd birthday with her. He even describes how amazing she is alphabetically. In the same episode, he is shown to be very protective and attached to her, forbidding her from seeing her boyfriend, Louie. Richard revealed that he did this because his father had left them. He was afraid that his mother would like Louie more than him and he would lose her too. In response to this, his mother comforts him and shows that she cares about him too.
Richard has not interacted much with Louie before the events of "The Man." But when he does in the mentioned episode, he establishes a major relationship with him. At first though, Richard was afraid that his mother would like Louie better than him and because of this, he treated Louie unpleasantly. After a man-off, Richard stops his mean treatment, and even accepts Louie as his dad.
Richard's biological father left him and his mother when he was young, for unknown reasons. After Frankie finally returns, he scams Richard into giving him possession of his house. Eventually, he regrets having hurt Richard and his family. While Granny Jojo may not think so favorably of Frankie, Richard still loves him, and he even asks him to reunite with him.
Richard has shown much confrontation with Mr. Robinson in the show. In "The Poltergeist" when Gaylord cut his two dollar clip-on tie, and in "The Wand" when Richard fought him using Wanda. The most important role was in "The Tag" when they fought over a trash can throughout the episode.