One of my favourite tools for an engagement is #dehashed. They essentially offer a service to search leaks and get creds. Here's a quick one liner to take the JSON output from their tool and generate a creds list for whatever purposes you may need:
cat dehashed.json | jq '.entries[] |{email,password} | select(.password != "") | (.email) + ":" + (.password)' | sort | uniq | sed s/\"//g