The killer crossover is the move which "breaks" the defenders ankles. When done correctly (and well) it cannot be defended - even by MJ.
I do want to set the record straight about who has the best killer crossover. Sorry AI, for all of your incredible skilz, no one did it better than Tim Hardaway. Please.
The single greatest example of a killer crossover is seen here:
This takes place in the ACC final in 1995 between UNC and Wake Forest. The perpetrator is Randolph Childress. The victim is Jeff McInnis. First, Childress's crossover move is so devastating that McInnis falls over as his ankles interlock. Then, to add insult to injury, Childress hops a couple of steps over, and tauntingly beckons the prostrate McInnis to get up, before he cooly drains a 3-pointer.