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"..
Do not simplify the design of a program if a way can be found to make it complex and wonderful.