Used to work at a large law firm and the old guy who delivered by-hand mail etc got leathered at the xmas do in a very large, posh hotel.
During the course of the night:
Slapped one of the secretaries
Insulted another so aggressively that she went home crying
got the office junior smashed on red-wine until he inevitably puked everywhere, on himself, and some others- his mum had to come and fetch him
then as a finale went up to the MD of the entire firm and said 'you're a ****. the biggest **** of them all'
All relatively entertaining and scandalous but the best part of it was he came to work on the following Monday completely unaware of what he had done. He even started giving it large about how everyone else was 'boring' and nobody else was even drunk, we were all dull etc.
He didn't even believe us at first when we updated him with his antics but soon got the picture when the MD called him into his office to explain himself. Amazingly he didn't get sacked but he did have to spend the entire day apologising to everyone including the office junior's mum.
I nailed 3 e's that night without anybody suspecting, though in fairness the old fella's antics probably eclipsed everyone elses