Over, all day long. Actually, I don't think I could trust anyone who went under. According to my sources (who are very reliable), 95.7% over people who roll their toilet paper under have psychopathic tendencies. Think of this thread as a "Get-to-Know-You" sort of thread.
I hope that most of my 11W brethren are with me in the TP Preferences. I bid thee, good day.