This was about 9-10 years ago on pmUA, and not a record for the number, but my record for annoyance in gate changes:
We arrived at ORD C27, then had to run to catch an ORD-PIT from F-something (mainline at the time). Sat on that plane for 2 hours before they told us we needed to get off and go to...C27. Better than cancelled, but still...