Wasder said:
The trick is to really get them to believe you.
I don't get why "my mom's dead..." thing works on people... Whenever I go down the "I fucked your mother" route, generally facetiously and if possible done with a TF2 Spy voice(even though more often than not they take it seriously), and I'm met with a "my mom's dead" comeback I generally reply something along the lines of "I know
", "Now she is" or "And if she wasn't she'd die of shame thanks to you".
@OP: Worst insult ever... I don't know, they're all generally uninspired. "Fag!" probably... Simply because it's sooo generic.