Oh, I have many, many fun stories about AD&D.
Our Ravenloft party was always fun. Combine that with an inexperienced and slightly vengeful DM, and we had a blast.
While in an inn at Barovia, we receive a personal invitation by a certain Strahd Von Zarovich. I was a priestess of Leira, and after a (very easy) non-weapon proficiency check, I told the rest of the group that this nice noble just MIGHT be the fiercest vampire in a land... full of vampires.
Of course, being slightly suicidal, our gnome druid and the fighter start concocting a plan. "Hey, Mr. Alteration Mage, don't you have a spell called "Item" in handy?"
"Why, yes, I can memorize it for tomorrow. Why?"
"What does it do, again?"
"Well, it greatly reduces the size of objects. A strong impact may cause the item to revert to its original size. We used it to go spelunking that crypt, remember?"
They rush to the local church with a big barrel and pay the local priest to bless it.
Well, the scene then can be resumed by us riding towards Von Zarovitch's Castle the next night, armed with our dim wit and a Itemized barrel of holy water in our hands. The dorr is opened by Strahd himself (?!), who is promptly greeted by a measure and a fighter throwing the tiny barrel into his face.
Our DM had a rough time calculating the damage he had taken. Yes, it was before Van Richter's Guide to Vampires and the whole "Elder vampires are immune to Holy Water".
He puffed away in his gaseous form, cursing us in good English, while we suddenly felt the rush of a full level and being just a XP away from the next one. Good times.
Also, we discovered that Transmute Rock to Mud can be terrible for that climactic final scene the DM had planned for so long. After using that spell in two big encounters, mysteriously all dungeons in Ravenloft were conveniently carpeted in a nice wooden floor. Yes, even the thousand old undisturbed tombs of yore.
"Don't ask it!" said our DM...
Finally, just from the top of my head, a phrase that was uttered in utter disappointment by a fellow player and friend, after botching for the third time in a very, very short period of time.
"Fuck it, these dice are completely random!"
Epic.