Romulan Warbird or the Saturn 5 rocket.

The Apollo Lunar Lander. The only real space ship we ever built. (I guess we built another one for the next trip now, though, so I'll go with "ever flown")

People can say it's ugly all they want, but, as an engineer, it's exquisitely designed for its purpose. That's true beauty to me.

The Heart of Gold, from The Hitchhikers Guide. Plot armour taken to its most literal extreme.

Lexx is one of my favourite ships. It was such an oddball show as well.

Mistake Not My Current State Of Joshing Gentle Peevishness For The Awesome And Terrible Majesty Of The Towering Seas Of Ire That Are Themselves The Mere Milquetoast Shallows Fringing My Vast Oceans Of Wrath

Not sure in what context you're asking this question, but my answer is the International Space Station. I love how it's possible to see it at random sometimes at night, and the way it crosses the sky just looks different compared to a regular airplane flying at night.

Does the TARDIS count as a starship? That's kinda cheating though.

I’m torn between the Defiant and Serenity

While not exactly a space ship, I'd say Thunderbird 2

The Kestrel Cruiser from FTL. Even though it's not even the coolest ship in the game, The Kestrel is still the most nostalgic for me.

It brings me back to when I first played FTL a decade ago. I was a kid back then and loved the game so much, I even built and painted a cardboard Kestrel model.

The Red Dwarf :)

I can't decide between The Planet Express ship and the space Van from Spaceballs.

Gotta go with the Normandy SR-2

And her crew 😢

I am mildly obsessed with the Saturn V. It's just such a feat of engineering and human cooperation.

BC-304. The Prometheus was so ugly in comparison.

Shout-out to the basic cable show that was giving us Hollywood-level visual effects effects as early as 2004.

Atlantis gets visual effects Emmy nomination

The Atlantis Effect: An Interview With Mark Breakspear

GW: Visually, which is your favorite episode of Atlantis so far?

MB: “The Eye.” The Rainmaker team created their own CG software to create the stormy water for the ocean. The level of detail and control has never been seen in TV effects before. Dan and Jose at Rainmaker pulled out all the stops and created mind-blowing shots. I think we went about 3.5 times over budget on that one — but you can’t get away with crap. You guys can spot that a mile away, and nothing kills a show quicker than cheap looking effects.

Moya, from Farscape

Daedalus.

The Swordfish from Cowboy Bebop. I recently bought a rather expensive model of it. Totally worth it though.

Enterprise refit. Loved the original Enterprise and the Enterprise D when TNG came out, but there was something magical about seeing the refit on the big screen.

I take one standard Culture GSV and Mind please.

A-wing Interceptor from Star Wars.

https://en.wikipedia.org/wiki/A-wing

What? No love for the Millennium Falcon?

Erebus class titan from EVE Online

My pick was already mentioned (Rocinante) so for second place I'm gonna mention the Galactica.

Definitely the Soyuz, it's hard to beat the safest and most reliable spacecraft

If we're talking fictional I'd say Serenity, I love what's essentially a tramp steamer in space with little nooks and crannies for less than legitimate cargo

The Hail Mary currently. Just such a cool ship from a fun book. To think about what would go into building it and what that means to humanity is humbling.

Other notables:

• Enterprise E from First Contact because it looks cool.
• Cygnus from The Black Hole
• Sulaco from Aliens
• Trimaxion Drone Ship from Flight of the Navigator
• The Abominator-class Offensive Unit Falling Outside the Normal Moral Constraints (my usual favourite lol)

Imperial star destroyer

While I know it's easy to hate on everything MCU these days, I do still absolutely love the Milano from Guardians of the Galaxy 1 and 2. The design doesn't feel practical at all, but it's still a really fun to look at and agile ship, which is something a lot of sci fi doesn't really depict very well.

Oldie but a goodie: the Star Fury fighter from Babylon 5.

The USS Defiant. Coolest ship in Starfleet.

The Intrepid class of star ships.

The Yamato!

https://youtu.be/zNT3un2JmJU?si=t0GrB3x07IsN-5Rn

When it comes to fiction, I'm quite fond of the Gunstar in The Last Starfighter both in appearance and in its surprisingly practical pilot/gunner and mobility systems.

The U.S.S. Enterprise, "NCC-1701, no bloody A, B, C or D!"

Hard sci-fi: The Rocinante

Floppy sci-f: The A-Wing

I really like the Nostromo from Alien (1979). The Icarus II from Sunshine (2007) is pretty cool, too.