I've been finding lots and lots of great sites that I look to when I need a little help with ideas. I'll link them here so they are easy for all of us to find. Check back often. I'll keep adding!
Plinky: Plinky gives a writing prompt every day (and they archive them too). Some are serious, some are funny. Some require you to dig deep inside for an answer, some just ask you to share your favorites. I've used this with my creative writing classes and the prompts are pretty good!
Figment: I haven't used Figment a lot. I have signed up at the site and receive their emails. The prompts require a bit more thinking and writing. But they do look fun!
Creative Writing Prompts: I love this site and so do many of my students. It looks like a page of numbers, but hover over those numbers and great writing ideas appear!