That's a great post and I've been using these plugins on most of my sites (in addition to some alternatives of the Exploit Scanner).

My favorite one is definitely the WordPress File Monitor, as most of the hacked sites I'm dealing with are due to hacked account on a shared hosting or a plugin vulnerability that allows for shell upload, or anything like that. Catching that break in an early stage allows you to take actions and prevent future issues, and rewind through the logs and see how/when it happen exactly.