Useful Drupal modules

Click on the module name for notes, comments, patches.
Recommendations (for and against) are my personal opinion only and may be out of date. Feel free to email with corrections/suggestions.

Why haven't you mentioned Drupal 9? As of December 2021 I've updated most of the sites I look after to Drupal 9 (experience: mixed). I haven't decided how to label future version compatibility as D10 will be coming soon as well. The upgrade_status module is superb. You're bound to have issues with composer. Also watch out for a nasty session headers bug with redirect_after_login.

(1 modules in list)
Module name or machine name
Any text in the notes
Name D8 Personally Tested Last Updated
Spambot (spambot) 2019-04-05

d.o. page

"Essential"

Scans email addresses/usernames/IP addresses against the stopforumspam.com database and then blocks or deletes the accounts.
You can set the threshold - i.e. how many times an email address needs to be listed in the spam database before action is taken.
You can also have it scan your entire existing database, not just new users. (It does this via a configurable cron run.)

Tested with D7.