In your /etc/suauth or /etc/sudoers or /etc/su* file, you can change your user account to NO PASS for su to root:
However, I'm not sure how wise this would be to do. It's your system, but if anyone should get your user password then they've got root, and that's not good. But, Linux is about choice, and it's your choice to do it or not. Be careful.
Hope this helps.