Probably the biggest laugh out loud I ever experienced was many, many years ago on Chessy.
I was fairly new to the game and in a great old Chessy guild named ASC(after the classic Monty Python and the Holy Grail commune)
One of our guildmates staged a very elaborate ingame wedding in the field outside of Fel Vesper. Weeks of planning. May have even been a gm or counselor there to officiate but not positive.
The very well known Scarlet & her daughter Sundina were in attendance and there was a full wedding party with matching outfits, etc..., etc...
Kind of a 'you had to be there' thing but right in the middle of the way too serious ceremony one of our guildmates said "**** this" and ev'ed the entire wedding party to death. He actually icqed me right before he did it and I was laughing too hard to stop him.
Some of you old Chessy people may remember the group:
Irissa,Raeboth Vishod,Scarlet,Sundina,Grendel,STRIDER(me),Chuck Zito,Blackard of Isles,Aun Dornback.
That without questuion is one of my alltime best UO memories