Linux VPS servers

All users have their own separate log files and every domain has their own logs - eg: sitename.com

Exim:
/var/log/exim_mainlog
/var/log/maillog
/var/log/exim_paniclog

Apache:
/usr/local/apache/logs/error_log (404 not found errors, etc)
/usr/local/apache/logs/access_log
/usr/local/apache/domlogs/sitename.com (individual site logs)

Logins:
/var/log/secure /var/log/logins_log

Messages:
/var/log/messages

cPanel:
/usr/local/cpanel/logs/access_log