In the UK, Cineworld has a £18/month deal for unlimited movies. Based on discounted/special offer ticket prices of ~£8 you need to watch about 2.5 movies a month to make it value for money. Having used it for 10+ years now it’s still good value for me.
In the USA the cost of a single adult movie ticket is ~$15. Charging less than that per month for unlimited movies was puzzling.
Depends on where in the U.S. where I am currently adult tickets are $11.