My DM is pretty good at these sorts of situations.
Recently, she managed to set up, without any of us seeing it coming, a little situation for my greedy rogue characters.
The party were trying to uncover a sacred relic from a tomb, we needed it to give it somebody who could utilize it to stop an impending invasion. Now, my character is a greedy, two-timing rogue, and whilst he liked the idea of the relic, which happened to be a giant flawless ruby the size of a hobbit's head, he was more interested in all the other treasures that could be found. Sure enough, during our dungeon crawl, the central chamber was full of gold coins, which my rogue gleefully rolled around in before trying to stuff as much as he could into he satchel. Now, when our party leader got too close to the relic's pedestal, the place started to collapse, which was bad. The platform we were one jutted suddenly to one side and we were all thrown to the edge of a precipice. Everyone had to roll to grab onto things they passed, and got multiple chances to do so, except for me and our healer. I only got one chance, right at the edge, which I passed with ease. Then, our healer went by, and we both had to roll, which we managed, and I ended up there, one hand on the cliff edge, the other holding our healer, who is a nice girl OOC too.
Then, the fucking ruby fell off its pedestal, and slide down across the rock, before eventually falling past me and the healer. Then, the DM gave me a choice. I could leave it up to the healer to catch it, but she had penalties for using one hand and for the situation, and the chance of her successfully catching the gem were slim. Or I could try and catch it myself, even with all the penalties, I could probably succeed, but it meant letting go of either the cliff edge or the healer to do so.
I had to choose between our healer, my greed, and the fate of possibly an entire nation.