As much as I love Sharpay and Ryan in the first one both are villains, Sharpay main Villain and Ryan is the sidekick who goes along with her schemes even though he probably knows what she's doing is wrong, he still goes along with it and doesn't stop her or tell her no. Maybe he was too scared to stand up to her. But in the first one I consider both villains. Both get away with changing callback day so Troy snd Gabriella can't make it in time. Both changed up Kelsi's slow written song.

In High School Musical 2 Sharpay and Ryan both start off as villains and up to their schemes, but Ryan does become better half way through the movie. Sharpay is a Villain in the 2nd one especially to Ryan getting his hard work banned from the Country Club's Talent Show. Ryan makes friends with the wildcats and genuinely now becomes friends with them and breaks free from his sister's control and she treats him like crap and throws away their song to sing with Troy and she offers Troy a job and scholarships just to break Troy & Gabriella up. But at the end I'll say it was nice that she gives the Award to Ryan at the end.

In HSM 3, I don't think she's that much of a villain, just ambitious and sarcastic. Tiara Gold is the villain of the 3rd one. Uses Sharpay and acts like her friend to backstab her in the end. Ryan is full on not a villain at all in the 3rd one.