This is an amazing movie! I've hated horror movies all my life but this one actually isn't scary -- expect to see a stressful yet overall satisfying journey that keeps your palms sweaty and your eyes tearful by the end. Interestingly enough, Train to Busan focuses heavily on the characters whom you get incredibly attached to, despite each having different motivations, desires, and feelings. You ultimately realize that the true enemy isn't actually the zombies: it's the horrible nature of people to act selfishly during times of crisis. This movie is definitely a classic and can be re-watched any number of times without becoming stale.
I might have a unique opinion here by saying that I absolutely loved Burton's version of Charlie and the Chocolate Factory. As someone who read the novel and watched this movie as a child, I was enthralled once again by Dahl's imagination in this version -- a perfect mix of whimsical and sinister. It is no exaggeration to say that it personified some of the deadliest sins of the youth, but still in a manner that is palatable and amusing. Depp's portrayal of Willy Wonka of a child in a grown man's body, despite being just downright weird at times, is still compelling enough for your heart to be warmed by the finale. I recommend this for people my age (Gen Z/Millenials), whether or not you've glimpsed this during your childhood, for its timeless themes that may make you reflect on your old, immature self.