Even if you like to come up with your own campaign settings and game ideas, it’s always nice to get a little nudge. Perhaps that nudge will come from a story you see on the news. Perhaps, though, as John Acadian notes over at Gnome Stew, it will come from the classified ad for someone to kill that pesky green dragon. As he also points out, of course, such an ad would also make for a great prop!
Maybe you’re looking for a richer base from which you can build your game. Perhaps what you need is a fully fleshed out campaign setting. In that case, you might be interested in Martin Ralya’s review of Midgard, the prolific Wolfgang Baur’s home setting.