It takes a lot of energy to zip around the stars standing akimbo in your rolled-down boots. So the best battlecruisers and starships have really powerful energy sources. But what's the most powerful spaceship or station, in terms of energy output? This isn't just an idle question, because we'll need to know which fictional technology to aim for, when we finally conquer interstellar space. Click through for our ranking of the least and most powerful spacecraft. (Hint: It's not the Death Star!)

(Note: If I left someone out, chances are it's because I couldn't find any data. Feel free to add your own in the comments!)

The Enterprise-D, from Star Trek: The Next Generation.
Power source: matter-antimatter reactor.
Energy output: 6.8 x 10^16 joules, based on the amount of energy it would take for the Enterprise to do significant damage to a Borg cube, according to this guy.

The Narn's Q'Guan Heavy Cruiser, from Babylon 5.
Power source: nuclear fusion.
Energy output: 7.08 x 10^22 joules, according to this site.

Omega Class Destroyer, from Babylon 5.
Power source: four General Fusion 650 high-energy fusion reactors, using gelled deuterium as fuel.
Energy output: 1.83 x 10^23 joules, according to the Cycrow site again.

Colonial Battlestar, from Battlestar Galactica.
Power source: Tyllium reactor.
Energy output: 4.6 x 10^24 joules, according to the Battlestar technical site.

Babylon 5 Station, from Babylon 5.
Power source: eight fusion reactors.
Energy output: 2.5 x 10^24 joules, according to several sites.

Zero Point Module, from Stargate.
Power source: Vacuum energy, from a pocket of subspace.
Energy output: 10^28 joules, according to this guy's back-of-the-envelope calculations.

The Death Star, from the original Star Wars.
Power source: Some kind of "hypermatter" fusion reactor.
Energy output: It would need to generate 2.4 x 10^32 joules of energy to destroy a planet such as Alderaan. Upper estimates of its power run to around 10^38 joules, or as much energy as our sun generates in 8,000 years, according to this site.

Ringworld, from Larry Niven's Ringworld novels.
Power source: Solar energy, collected by "shadow squares."
Energy output: To keep the whole shebang spinning at 770 miles per second, you'd need 1.6 x 10^39 joules, or our sun's output over 130,000 years, according to this site and a few others. We have a winner!