Don't like it when people laugh at their own jokes before they even get to the punchline.
I feel like slitting my wrists every time I watch twats like Billy Connolly or even worse Michael fucking McIntyre. Just tell the bloody joke, if you're gonna laugh then just give yourself a golden star for being such a gift to mankind instead of ruining it.
Even worse is when people chuckle and you ask them "What's so funny?" and they respond "Nothing," Has gotten to the point where i hold some sort of immature grudge against the perpetrator until they redeem themselves.