In designing games, random generators can go a long way to help seed an idea. There are generators for just about everything on the web and we've found two of them useful time and time again, in all sorts of different scenarios. From the overarching concept for a video game to some ideas for the next quest in a Dungeons & Dragons campaign, these generators can really help you out.
Seventh Sanctum, run by Steve Savage, has been publishing generators since 1999. From generators for several types of names to ice cream dishes, wrestling moves and more there isn't much Seventh Sanctum can't help you generate. For those instances it cannot however a collection of similar generator websites are recommended by the author.
Donjon is another collection of generators with a specific focus on fantasy. Three are a few 'weird' and sci-fi generators there, too but the main strength of donjon is the provision of generators hich explicitly follow the rules of many tabletop RPG systems to help create NPCs, scenarios, worlds and more.