The Imperial Shuttle has very large, folding "wings" and a large dorsal fin. Despite this, the shuttle itself can only carry a few people, and with the technology of the Star Wars universe, the wings are completely unnecessary anyway (it's shown multiple times taking off and landing while the wings are still folded).
The Super Star Destroyer Executor. It is canonically 19 kilometers long, and while it is a fully functional warship, it's purpose is clearly more symbolic of The Empire's vast resources. A fleet of smaller ships could easily accomplish the same thing.
For a close second in length, we have the Eclipse-class super star destroyer from the Dark Empire comics (17 km, and outmasses the Executor-class). And by the New Jedi Order series the New Republic has a few such vessels of its own, specifically the Viscount-class battleship, expressly designed as a counter to the Super Star Destroyer and its ilk.
The novel Revelation Space features a kilometers-long spaceship called the Nostalgia For Infinity that, despite being built to hold over a hundred thousand passengers, is crewed in the story by only a handful of post-humans.
In House of Suns, each of the main characters has their own kilometers-long ship that they fly around in alone most of the time. One tense scene in the novel takes place in the cargo hold of a ship, which itself is akin to a vast cavern kilometers across.
In Stephen Baxter'sXeelee Sequence universe: the Xeelee Nightfighter. The cockpit is small, about the size of a room, but it's wings stretch out for kilometers in either direction, like vast sails. The purpose of these wings are never made evident, as the ship itself travels via teleportation.
Subverted/handwaved in E. E. “Doc” Smith's book Skylark Of Valeron: while the eponymous vessel was a sphere over 1000km in radius and has a crew of four, it needed to be that big to contain the navigational instruments necessary to cross intergalactic space.
Ellis Billington in The Jennifer Morgue has a yacht called the Mabuse. For a certain value of "yacht", anyway: the thing is a demilitarized former Russian Navy Krivak III-class missile frigate. She basically exists to say that Billington is richer than Croesus. With the missile tubes and other armament having been removed, she has more than enough space for a luxurious suite of rooms and a well-equipped occult surveillance operation.
The Red Dwarf is a kilometers-long mining ship that originally had a crew of hundreds. Three million years later it's crewed by a slacker who was in stasis for bringing a cat on board, a being that evolved from said cat, the ship's somewhat senile computer, a hologram of one of the dead crew, and, from series 3 onward, a robot butler they picked up on a passing asteroid.
Stargate SG-1 has Goa'uld Ha'tak-class motherships that are 700 meters in length, pretty much entirely to scare the hell out of primitive cultures as it lands and/or bombards them from afar. Spacious ornate interiors predominate. And yet by the end of SG-1, the Ha'tak is actually considered underpowered: the much more compact Prometheus- and Daedalus-class battlecruisers (195 meters and 225 meters respectively) immensely outgun it. Awesome but Impractical is pretty much the standard Goa'uld design philosophy: as Jack O'Neill notes in "The Warrior" regarding their infantry weapons, the Goa'uld build their military technology to terrorize, whereas the Tau'ri design theirs to kill as efficiently as possible.
The Tulip in Starhunter is a retired luxury liner repurposed as a bounty hunting vessel. Since her crew currently consists of three people and an AI, she has so much unused space that the crew hasn't even bothered to explore the entire ship. Which led to a rather weird turn of events in one episode when a Human Popsicle in an unexplored corridor thawed out.
While all Eldar vessels in Warhammer40000 have smaller crews than the Imperial ones (which have comparable crew densities to modern warships), the Hemlock-class destroyers fit this trope. They are escort ships carrying a pulse laser normally reserved for capital ships, leaving precious little room for crew other than the gunners and steersmen. There's also the Wraithships, which are several kilometer long capital ships that might only have a single living soul on board [[hottip:*:Emphasis on living, as the wraithships are piloted by the souls of dead Eldar within the ship's Infinity Circuit, with the one living being on board being the Spiritseer that helps guide the souls.]]
Referenced in Mass Effect 2: the Normandy SR-2 is considerably bigger than the first Normandy, and comes equipped with a spacious Captain's cabin. Several characters comment on the fact that, while the Alliance builds its ships for efficiency, Cerberus (being a criminal organisation with no oversight) can build to impress. Also, the SR-2 seemingly has fewer visible crew members than the SR-1.
The Polaris Raven in EV Nova is tied with the Auroran carrier for the title of largest starship in the setting at 1,200 meters in length. For all that size, it has a mere 30 crew, making one wonder exactly what it's doing with all that space when the Federation carrier is only 500 meters long but has a crew of 200, and the aforementioned Auroran version carries a crew of 250.
In X3: Terran Conflict the Dummied Out ATF Valhalla super-destroyer is easily the biggest ship in the game. In fact it's so big that A) it has serious issues with the firing arcs for its turrets, and B) it's wider than the jumpgates, meaning that if the player cheats one in and has it pass a gate while he's in the same sector, it bangs into the gate rim and loses its shields. The expansionAlbion Prelude fixed the second behavior but not the first, and that, coupled with the fact that it's not much better of a Mighty Glacier than conventional destroyers, means that it's largely Awesome but Impractical.
Pretty much every ship Tagon's Toughs of Schlock Mercenary has owned since their first one was meant to house a lot more than the under 100 troops the company comprises. Including an Ob'enn Superfortress, a Drop Ship from said superfortress that was rated for 25,000 men (needed some sleeping space though), and currently a cruiser meant for 6,000. They rely pretty heavily on the ships' AIs to run things.
The Absolution from Toonami is incredibly huge, but it only has one operator (TOM) and a handful of assistants (The Cyldes). Considering its only used as a broadcast center, who knows what they need all that space for.
The episode "Battle Of The Planets", from Invader Zim, has the entire planet of Mars being converted into a giant spaceship, piloted by Zim. Later on, Mercury is also revealed to be a spaceship, which Dib promptly uses to fight Zim, leading to a hilarious montage of Zim and Dib bumping the planets into each other and actually dogfighting. With planets.
While not a starship, the Soviet "Akula"-class[[hottip:*:That class was known to NATO as the Typhoon.]] The sub class NATO identified as Akula was a smaller attack boat that the Russians called Shchuka ('pike')]] nuclear ballistic missile submarines qualify. Due to the massive size of the missiles it was supposed to carry, desperate Soviet engineers had no choice but to make it ridiculously big, with large empty areas - a disadvantage for a submarine. They decided to fill said empty space with countless crew amenities, which ended up making the vessel perfect for its intended purpose - hiding for months at a time under the water in case of nuclear war. The relatively large space and comfort made sure mental stability among the crew was easily maintained even in stressful situations.
The Titanic was deliberately built to be the largest ship in the world.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
Is that what you meant to do?
You are saying this draft has a ready-to-publish hat it does not deserve and you are taking it back.