I'm pretty sure three was my highest. I do have very common double sneezes, I have that wierd condition where bright light makes you sneeze, so every step outside from inside results in two sneezes.
Since we're on the topic, does anyone here hate it when a sneeze cancels? You start to make that goofy "I'm about to F-ing sneeze" look and right before you do it just goes away? I hate that so much.