What do you do when someone says something antisemitic to your face?

Here’s what I don’t mean, there are plenty of other discussions about these topics:

• your feelings on the inside and coping mechanisms
• someone being ignorant and saying something antisemitic without understanding the ramifications/offensiveness (still bad) but also still willing to be part of a discussion

I’m looking for what are the best/worst/most outlandish things you’ve done and said, the times someone has told you Israel should be wiped off the map, or that Jews control the banks, or thrown pennies at your feet. Obviously not all of us have this experience, but I find most of us who have regular contact with gentiles have seen this at least a little. Do you go low? Do you go high?

I’m legitimately asking this so I can learn to fight back stronger.

I’ll go first. Someone who had already been racist and antagonistic to me told me that Jews killed Jesus. I told her “AND I’D DO IT AGAIN”
Not constructive, but it shut her up.