Ok this isnt asking people for stories about how a group was so fail but more like has there ever been something weird or bizzare you've had to do in an LFG or chose to do, heres an example of mine.
I was on my hunter and got into a UP group, I went for a bit noticing the tank not pulling good threat and having less health then me, a rogue, and the healer. I inspected him noticing he was in full greens, unsocketed, and 3 unspent talent points. Not only that but he had his chat turned off or wasnt listening to any of us telling him he had 3 unspent talent points so we group kicked him after the first boss, one problem nobody in the group could have a tank off-spec and there was no immediate tank, so i decided for fun i'd so off my 'tanking spec' which i use to solo wotlk dungeons which gets me up to 42k health fully buffed, and 35k health with 5 man buffs. Then the healer saw my pet and asked me, 'You think you could actually tank the way through the dungeon until we get a new tank?', I said i'd try it and ended up having my pet sucessfully tank all the way up to the last boss when we finally got a real tank in. So yeah for once I got to be a hunter who was focused on making sure i had more threat than trying to get rid of my threat, i found it fun, and probably one of the most random and weird things i had to do in dungeons if not wow.