Just got this command to see the big files in my system.
find / -type f -size +10000k -exec ls -lh {} \; | awk '{ print $5 ": " $9 }'
you can play with parameters ($5, $9) i think it is changing wrt your system.
Thanks to
http://www.cyberciti.biz/faq/find-large-files-linux/ for this valuable information