I heard one that really grated on me when I was at the Dallas Show in March. I was working through a box of vintage commons and the modern dealer at the next table was talking about breaking a case and he called the case hits "the kabooms." I am not particularly fond of the calling the prime cards "hits" but I accept it since there probably isn't a better, concise term for those cards.
But, to hear a grown man call them "kabooms" was just grating. I can see it being common among pre-teens, what with their less-than-fully developed language skills. But an adult? Yeesh.