Happy Valley is terrific too, but unlike Broadchurch it's stuck behind "buy now" on Amazon.
Broadchurch is very solid.
I gave Broadchurch a strong write-up a few fellow fans concurred with. I went down the UK crime telly hole. I ranked 10 but I did this very fast in about an hour right before the deadline. Given more time I can think of 5 more I should have ranked. I ranked them as follows and I really liked Happy Valley.
11 Broadchurch
15 Peaky Blinders
27 Sherlock
31 Line of Duty
32 The Bridge
33 Top Boy
34 Top Boy Summerhouse
44 The Night Manager
45 Shetland
61 Happy Valley
i put Line of Duty in bold because I rewatched just a week ago. I should have ranked it much higher. It's Broadchurch tier to me. I believe it's won the most awards of any British cops/crime show. Six hard hitting seasons with no let down. If you're into cop shows, I highly recommend it. It has the intensity of Broadchurch, but set in London. It's about the Anti-Corruption Unit (think internal affairs). Good cops investigating bad cops. Each season unique. Some outstanding writing, very strong characters who will leave an impression. 4 seasons free on prime. 5 and 6 can be had with a free trial of Britbox (which I pay for) or Acorn.