At the end of the day, what we need to realize is that minor good moments don't always make up for the bad ones. But also, being the villain in a story doesn't mean you're pure evil 100% of the time. Sharpay was imperfect, and I think that's what makes her such a good character. Despite her many devious schemes, we can all relate to her at some point or another.
My opinion? Gabriella Montez is the heroin of this story. And even if that makes Sharpay the villain, that's fine by me. Why? Because Sharpay is without a doubt the most iconic and unforgettable character of the HSM franchise