List taken from this 2022 BFI article, quoted below — I'm adding as I watch them. The list includes both the main suggestion and the 'one more to watch' pairing.

Horror cinema didn’t begin in 1922. There were ghosts in the machine as early as 1896, when the medium’s early magus, Georges Méliès, packed a giant bat, the Devil, various phantoms and a final vanquishing by crucifix into a spooky three minutes.

Adaptations of gothic classics, such as Mary Shelley’s Frankenstein, Robert Louis Stevenson’s The Strange Case of Dr. Jekyll and Mr. Hyde, and the short stories of Edgar Allan Poe were already fixtures on the screen by the 1910s — and by 1920 the feature-length horror film wasn’t a scary kid anymore. Alongside a polished Hollywood version of Jekyll and Hyde, those German expressionist lodestones The Cabinet of Dr. Caligari and The Golem marked the macabre coming of age of a genre that wanted to frighten, disgust, and haunt us.

But as [this is] the centenary year of both F.W. Murnau’s unofficial Dracula adaptation Nosferatu and Benjamin Christensen’s witchy pseudo-documentary Häxan, 1922 seemed the ideal place to begin our year-by-year rundown of frighteners.

Why year by year? Because it’s a better way to plumb the dark corners of horror’s cinematic history than a straightforward top 100. Selecting just one film per year leaves you with some nightmarish decisions for vintage years like 1960 — Psycho, Peeping Tom, Eyes Without a Face, or Black Sunday? — and 1973, when December alone saw the release of The Exorcist and a double bill (!) of Don’t Look Now and The Wicker Man. And who really, for 1954, wants to pit Godzilla against the Creature from the Black Lagoon?

Yet by travelling through the history of horror a year at a time, we can get a sense of the evolution of the genre — the strange, contorting, lycanthropic process by which we arrive at the fertile market we’re living in today. Bad moons rise, and purple patches come and go: the arrival of Universal’s gothic monster cycle and Hammer; the birth of the modern zombie movie and the slasher; the shots in the arm of J-horror and — though let’s not call them that — the ‘elevated horrors’ of the 2010s. But the journey also takes us through some barren terrain when either censorship took the fun out of the genre (the late 1930s) or audiences simply seemed to lose their thirst for it (the late 1940s and early 1950s). Even on these wind-blasted heaths, however, gems are to be found.

Before we get started, an arbitrary ground rule: we’ve omitted any horror films appearing on the IMDb top 250 list on the grounds of over-familiarity. So no Psycho, The Exorcist, Jaws (1975), Alien (1979), The Shining (1980), The Thing (1982) or The Silence of the Lambs (1991). The internet already knows and loves these films. We do too. But in picking over the carcass of a century of terror, we just wanted to keep things fresh.