Camera Obscura by Lavie Tidhar
Although technically the second book in a trilogy, all of the books in Lavie Tidhar's steampunky "Bookman Histories" can be read as individual works without knowing the other material. Set in a world where lizard aliens from outer space take over Victorian England and become the rulers, Camera Obscura is a sort of noir mystery wrapped in steampunk fantasy goodness with an immensely likable lead character. Tidhar is one of the most original writers working today and should definitely be read by all.
