Characters that liked Steve
As we all know, Steve's character was that of an annoying geek. And while other characters would occasionally stick up for him and had their moments of being nice to him, only three characters on the show wholly liked him: Mother Winslow, Myra, and Richie.
Steve/Mother Winslow: Steve and Mother Winslow were close friends for the entire series. Unlike the others that lived there (besides Richie), Estelle always enjoyed Steve's visits and considered him one of her surrogate grandchildren. Further, she was one of the only characters that was aware of just how abusive his parents were to him.
Steve/Myra: Myra loved Steve the way Steve loved Laura. In fact, she loved Steve so much so, that she had his picture all over her room on the walls, on the rug, on her blanket, and even on her pajamas. And even though, Myra crossed the line when Steve dumped her in the final season, you could definitely sense her hurt in the situation. There was rarely a character that loved him that much.
Steve/Richie: Steve and Richie were fairly close. In fact, Richie would affectionately call him "Uncle Steve". Steve would also occasionally help Richie out in various situations: helping him overcome his fear of the dentist, helping him with a science project, and helping him and 3J fend off a group of bullies at a park just to name a few instances.
Not that the other characters didn't like Steve, like I said, they had their moments when they were nice to him. It's just that Mother Winslow, Myra, and Richie were the three regular characters that were nice to Steve on a regular basis.