How can I come up with fresh and unique ideas for a novel?

I have a lot of ideas, but they've already been done. I'm really trying to avoid these predictable things that show up in tons of stories and movies like the evil monolithic corporation that cares about only money, the little guy from humble beginnings who makes it big against all odds or the most annoying thing: a 99.9% happy ending where nearly everything turns out okay. I don't want to nuke the world or have seemingly friendly aliens come down only to destroy everyone. Does anyone know how I can come up with genuine ideas that haven't been done before?