Interesting files for apache service...

lfi-apache.txt

# contains credentials 
/etc/passwd
/etc/htpasswd/.htpasswd
/etc/apache2/htpasswd

# contains logs : Log Poisoning might be possible with LFI
/etc/apache2/logs/access.log
/etc/apache2/logs/error.log
/etc/apache/logs/access.log
/etc/apache/logs/error.log

# phpinfo() : disable_functions and other specifications to be checked
/etc/apache/php/php.ini
/etc/apache/php5/php.ini

# general information about which file is where n stuff
/etc/apache/conf/httpd.conf
/etc/apache22/conf/httpd.conf
/etc/apache22/httpd.conf
/etc/apache2/apache2.conf
/etc/apache2/apache.conf
/etc/apache2/conf/httpd.conf
/etc/apache2/default-server.conf
/etc/apache2/envvars
/etc/apache2/httpd2.conf
/etc/apache2/httpd.conf