she was kinda cool in rebellion story but annoying in the original story imo. ill elaborate. hes basically really entitled and has a punitive, reductive, cops mentality about things. i dont like how she spoke to kyoko, her naive and idealistic view of the world is stupid, even for someone her age, shes basically just really sheltered from actual suffering and was hoisted by her own petard so to speak. its unfortunate that kyoko was dragged into all that and made to feel bad about herself by someone who never had to work or struggle for anything in her life.
however, sayaka is madokas best friend before homura. apparently, sayaka and madoka met when sayaka defended her from bullies. so she has this kind of knightly attitude that is also present in her character design. it's also because of this that homura must destroy sayaka and sayaka is most likely to get in homura's way. afterall, homura was amoral from the get go, from before her first loop she had already given up on humanity. so its really funny whenever sayaka and homura interact bc their value systems are as completely different as they can possibly get. so i like her in the sense that its funny for homura to have to deal with her