Ads that play sound
THIS. It even gets better sometimes when they don't start playing immediately (haven't figured out why due to adBlock now) but after a while. Nothing makes you want to kill someone more than full sound screaming voice "THIS NEW PENIS ENLARGEMENT TECHNIQUE HAS BEEN PROVEN TO WORK BY THOUSANDS OF SCIENTISTS"..
"You're a creature of the night, Michael. Wait'll Mom hears about this." -- from the movie "The Lost Boys"