What's the coolest thing you have done on the Sims? It can be a storyline, gameplay, a sim you've created, and they came out fire, or a build. Even if it isn't "groundbreaking", but you're still hecka proud of it.
On Sims 3, I made a cool storyline with a crime boss and he had a family and his oldest son ended up with the Good trait, and they had tension. I didn't even plan for this. Sadly, my old computer chose that time to break, so I didn't get to play it out. But I was proud of my evil sim, his accomplishments (he was a wizard, too) and then his family and the kids.
On Sims 4, I made some cool builds that I'll add pictures to. I am also proud of my Supernatural game where I customized all the worlds and created cool stories of all the suprenaturals. The drama, the friendships, the organizations. Super fun.