One year, we decided to pass the new year eve in an uncle's house at some god forsaken hole with our dog. After a neverending trip during wich our dog farted in the car, we finally arrive. The said uncle was a radical ecologist, wich is not a problem per se, except when his only conversation subject is about the ecological collapse, not the ideal subject for a good atmosphere, with in addition to that my sister's BF, who was with us, doing his Mr. know-it-all show. Then we went to sleep, and i realize that i forgot my earplugs. No luck, everyone in my family was snoring very loudly, including the dog. Result: i didn't sleep at all and looked pretty much like a zombie the next morning.
Worst one since I cut ties with my family was my worst-ever flare up of stress-induced GI issues that turned into intermittent vomiting episodes lasting from christmas eve until I went to the ER on new year's day a few hours after midnight, ruined a little roadtrip my fiancee and I planned. Plus my work had just switched (worsened) our health insurance providers (effective at midnight jan 1) so getting that sorted out was a nightmare too.
Ones with my family idr, really. The norm was a mess of alcohol, gaslighting, and badly-veiled contempt for everyone (present, not present, unfortunate enough to be a stranger passing by, etc) usually with extremely disorienting travel involved. Even the cyclical vomiting is preferable.