Most science fiction series dealing with space travel have thier Capital Ship, and by Capital Ship I mean a ship that you see it you instantly know what series its from. Stargate has the Daedalus-Class, Star Trek has the Enterprise, Doctor Who has The Tardis, Babylon 5 has the Omega-Class Destroyer and Firefly has Serenity.
But even though all those ships are cool, they cant stand up to the coolness of a Colonial Battlestar. While not as technologically advanced as the other ships mentioned above, (This quick tip is about the Re-imagined Battlestars). The Battlestar in its own right is one of the Coolest.
The Battlestar is like a Space going aircraft carrier depending on the Class they can have anywhere from 40-120 Vipers on board, and launched in a matter of minutes from thier massive flight pods. Battlestars where also build for the long hual, with high efficiency water recyclers and air purification units a battlestar could remain deployed for years. They also had munitions production facilities, and some even Viper production facilities.
Because Re-imagined Battlestars were more conventional than thier 70s counterparts, instead of energy shielding they had extremely tough armour plating capable of withstanding Cylon weapons fire, missiles and even Nukes. Instead of being armed with Laser turrets and energy weapons Re-imagined battlestars were armed instead with Nukes and missiles and massive ship to ship bullets.
A battlestars Faster than light drive operated differently than the FTL drives in other Sci-fi series. Instead of getting from point A to B very fast, it worked by imputting a set of coordinates into a jump computer, then instantaneously jumping the ship to those coordinates.
With all that being said, afters seeing them in action in the TV series, Battlestars in my opinion are the coolest and most badass Starships I've seen in any sci-fi series.