CSS3 Animated Spaceship Flight
This creation is not purely done using CSS3 but some of the great uses of CSS3 are shown here. First of all, the spaceship is just an image which is animated using CSS3's animation and @keyframes properties. The most amazing thing you can see here is the background, no images have been used to create it. It is created purely using CSS3's gradients.
Basically, there are multiple radial-gradient used to create the starts and then the whole gradient bunch is repeated to create a repeating pattern of stars. The stars will look great in every browser except Internet Explorer while the animation will only work in Firefox and Webkit browsers.