(note: the ranking segment begins ~27:55 and includes his first four projects)
Alex Garland got his start as a screenwriter, most notably with his collaborations with Danny Boyle, including Sunshine (2007), 28 Days Later (2002), and The Beach (2000) which was based on his novel. In 2014, he transitioned to writer-director mode, helming four feature films and a limited series* to date. I'm sure I'll be revisiting his work in the future as he continues to make movies, but for now... here is how I would rank these