As a writer, this topic from Long and Short Reviews was very appropriate, particularly since I'm in discussions for a three-book series at the moment, so needed to be creative at a moment's notice. What does actually spark my creativity?
I've posted previously about how dreams are one thing that I get ideas from all the time. I tend to dream very vividly, and can often come up with full scenes which end up incorporated into stories. My novel Photograph was heavily based on a dream I had about two sisters and their shared dream of escaping into the local theme park, so I will always use dreams as a resource.
Another source is songs. I've often wanted to include a downloadable file with my stories so the reader can play relevant songs for each scene - almost everything I write has its own soundtrack, and often songs will influence the title as well. It's only a shame that I can't actually quote from song lyrics without running up against laws, because I've often wanted to do that as part of a scene.
And finally - films. If I find myself interested in an underused character or plot thread in a film, I may borrow them or it and develop it further in a story, although I'll change character names to avoid getting sued. Films can be a great source of ideas.
So what sparks your creativity?