3. Stuff Packs (The Sims 3)
Take the Master Suite Stuff DLC, for instance. Among other things, it includes a 40s-inspired chair. Which is great if furnishing the virtual homes of your Sims is as important as furnishing your real home. Given that this DLC sells for 10 pounds (or 20 US dollars), you could always put that money towards buying a real chair.
And it is not that the game itself does not come with an assortment of furnishings and quite a few chairs for your Sims to rest their virtual butts on, making this DLC a bit pointless.