SPOILERS FOR LOST MINES OF PHANDELVER AHEAD.
So myself and a friend were playing the Lost Mines of Phandelver campaign, with another friend DMing. My character was a male half-orc barbarian named Tiffany, my friend was a human fighter called Kal, and the DM had a drow ranger called Traxis.
We were searching for Kragmore Castle when we found an abandoned town home to an adult green dragon. Kal decided to persuade the dragon to help us defeat the Goblins in Kragmore Castle, to which the dragon agreed, but on one condition; we'd have to hand over all our magic items. I had a magic sword that I was quite attached to but after narrowly avoiding the dragon's acid breath I handed it over.
We got to the castle and managed to kill the goblin king while the dragon rained death upon dozens of other goblins, but we were very badly injured. We staggered out of the castle, only to find the dragon waiting for us. He demanded all our gold in exchange for our lives and we were in no position to protest, so we had no choice but to hand over every single coin.
After resting up, we decided to sneak back into the town and try to steal some of our items back. However, when we arrived, we discovered a group of dragon cultists preparing a tribute (a huge chest of gold and gems) to the dragon. We pretended to be fellow dragon worshippers and joined with the cultists, partaking in their rituals and whatnot. The following morning, as the cultists were preparing to deliver the tribute, we attacked them and wiped them out with no particular hassle. We then picked up the chest and ran out of town…
… Only to be stopped by the dragon. Kal pretended that the offering was a token of friendship for the dragon, and the dragon was pleased and invited us back to his tower. The dragon returned to his tower and we ran back to Phandelin before he discovered our escape.
TL;DR – paid a dragon magic items to help raid a castle, got beat up by the goblin king, dragon took our money in exchange for our lives. We then infiltrated some cultists, killed them and took the offering intended for the dragon, but the dragon stole that too.
By far the most fun I've ever had playing D&D.