No. 10: NASA Night Launch

What an appropriate Firefox theme to start off the Top 10 countdown! The NASA Night Launch theme isn't kicking off the list, but it's blasting off anyway. The only thing that really distinguishes this theme from other polished dark Firefox themes is the shuttle image that "launches off" when a page is loading. See, you're traveling to another planet on the World Wide Web universe!

Snark aside, the shuttle imagery throughout the browser looks fantastic, and it's compatible with a long list of extensions. It's also a nice tribute to the STS-116 mission.