Collective Hosts File
The Collective Hosts File Project strives to collect as many nasty domains as possible (phishing, malware, tracking, etc.) and puts them in one big file for your convenience.
View the sources and whitelisted domains.
If you're using Pi Hole, you can simply run
curl -sSL https://hell.sh/hosts/pihole.sh | sudo bash on the Pi Hole machine.
For all other purposes, here are the files:
The UNIX timestamp of the last list update is stored in https://hell.sh/hosts/etag.txt