Worst I recall was a near death session. It was 1989 in March and I was in the Outer Banks. It was a huge Nor'Easter and breaking on the piers. I decided to paddle out just prior to the clean up. As I made it to the outside a freak set came in and started to break about 100 feet past the current zone. I scrambled to make it to the outside and just as I started my duck dive of the first wave, the power of the wave ripped my board from my hands underwater and broke my leash. I was about 200 yards off the beach in a full suit, booties, gloves, and a hood. I still remember this more than any other day and I have taken beatings around the world!
Runner Up was Parlours in Barbados at about 15 foot faces. I actually pulled into a close out and the wave pushed me no less than 20 feet under with 6 to 8 waves in a set. I did not panic nowhere near like the Outer Banks session since it was only trunks.