1979-ish.
Four of us high school buddies played together. We rotated GMing and each played 5 characters. Most of the time we'd travel around together, with our henchmen, fleets, mercenaries, etc, etc; then we'd get to whoever was GMing's Dungeon, where each of the 3 players would chose 2 of his characters to make up a party of 6. (Sometimes we'd all send our parties in at the same time.)
Stan was the Monte Haulest of Monte Haulers. My Wizard got a Staff of the Magi at only 4th level. He'd try to build these outrageous monsters and deathtraps, then fill it with ungodly treasure, rationalizing that we'd never get it. And almost 100% of the time, he was flat...out...wrong.
The climax of this came when we had gotten high enough level to penetrate to the mythical 10th level of his dungeon, which was a great vault of treasure filled with monsters in suspended animation - all the monsters and treasure that was required to keep refilling the dungeon over and over again. Guarding the entrance of this was his most dreaded monster of all....The Solder Monsters. Intelligent bits of molten metal that would burrow into you, causing damage. Surrounding the entrance was a great field of slick ice, so slick that you could not walk upon it (this well before Balance checks and the like).
Well, we got down there and were almost wiped out in short order. So we retreated and spent a couple of months (IC) preparing...
We went to a far northern land and learned how to ice skate! We prepared scrolls and wands and everything we could think of with various Fire and Ice spells. We prepared Wishes, potions, scrolls, everything and anything.
We go back in. Stan has no idea what we're up to. The Solder Monsters attack. We barrage them with Cold spells, to some small effect. We Heal each other almost constantly. Then....we Wish them all away.
Stan was dumbfounded. He hadn't even considered that option. He tried to limit the number we could wish away, but we were prepared for that, with more Wishes.
Then we get to the Ice Field...and pull out our skates! Man, the look on his face was priceless. Heck, we even had Wishes prepared for that too ("I wish we were expert ice skaters!") if he somehow objected.
The monsters start awaking and attacking in waves, but we're prepared for that too. Fireballs and Fire spells left and right, melting great holes in the sea of ice and killing scores of monsters. Followed by Ice Storm and Cone of Cold to trap the monsters who fell into the pools created by the fire spells.
In the end, Stan threw up his hands and gave us the lot. I think each character got something on the order of 5 million GPs and an open catalog of whatever magic we wanted. Was pretty much the end of the game, since those characters were now invincible!
We started a new game shortly thereafter, with only me as a GM.