Insidious (2011)

Most people think so. 78% of audiences gave it a thumbs up, by Google's archived audience score. Critics gave it 60%.

A family discovers that dark spirits have invaded their home after their son inexplicably falls into an endless sleep. When they reach out to a professional for help, they learn things are a lot more personal than they thought. Wikipedia ↗

Insidious is a 2011 American supernatural horror film directed by James Wan and written by Leigh Whannell, the filmmakers behind Saw who pivoted from torture horror to atmospheric supernatural terror. Patrick Wilson and Rose Byrne star as Josh and Renai Lambert, whose family moves into a new home where their son Dalton falls into an unexplained coma. When terrifying supernatural phenomena escalate — a figure appears in the baby's room, a bloody handprint marks the sheets, and ghostly figures are photographed — a medium named Elise Rainier, played by Lin Shaye, reveals that Dalton is not in a medical coma but has astral projected into a dark dimension called "The Further" where malevolent spirits want to use his empty body as a vessel.

James Wan's direction demonstrated that the most effective horror relies on what is suggested rather than shown — Wan created dread through quiet moments, barely glimpsed figures, and the oppressive atmosphere of a house that feels fundamentally wrong. Lin Shaye's Elise Rainier became the franchise's most beloved character. Insidious earned $97 million worldwide on a $1.5 million budget — one of the most profitable films of the decade relative to its cost — and launched a franchise of five films.