I wouldn't consider "5 Best Horror Movies" to be a clickbait title - it tells you exactly what you're going to get. The title of this article is a pure clickbait, IMO - it's designed to arouse curiosity and does not reveal what the article is about.

I guess it depends on what you believe article titles are for. I believe they should first and foremost be a tool for readers to decide whether or not to look at the article at all - therefore they need to accurately tell what the article is about. Sadly, most publishers consider headlines to be a marketing tool (with implicit assumption that the article is interesting for everyone).