Smilomaniac said:
The Destiny Ascension from Mass Effect is pretty big as well as the Ishimura. The rest seem... a bit awkward, almost none of them give you the impression that they're significant...
I wish there was a universal ship classification that extended to possible future starships.
Like superheavy, dreadnought, fleet carrier, colonial... It's sort of hard comparing the Asari "dreadnought" to StarCraft battle cruisers.
I like to use the one from d20 Future, a content book from the d20 modern roleplaying system back in the day:
Ultra light: Fighters, orbital shuttles and general small ships that are either short range or have very small crew complements.
Light: Destroyers, corvettes, frigates and other ships with less than a hundred crew members(at least for military vessels). Generally ships that are meant to scout or accompany/screen larger vessels, such as the Normandy.
Medium: Cruisers. Ships large enough to be independant patrol ships for extended periods of time or lead small fleets.
Heavy: Battleships and fleet carriers. Centerpieces and basically mini-bases that aren't meant to maneuver, but provide a platform for gun batteries, refueling, fighter launchers and so on. That would be the Battlecruiser from SC, though a large example.
Superheavy: Dreadnoughts, star carriers/motherships, colonial ships. Anything so large that it's practically a mobile base. They carry tens of thousands of people, can be self-reliant and serve great purposes. Their mere presence are enough to discourage most fights and are symbols in themselves of the combined force of a faction. I'd put the Asari Dreadnought here as a small example and the Ishimura as a large one.
Anything much bigger than that seems pointless to me to classify.
You have stuff like the almost 20km long super star destroyers [http://starwars.wikia.com/wiki/Executor-class_Star_Dreadnought], which kinda defy logic. At this point, you might as well have 20 1km long ships instead, which would be significantly more practical.
Then there are planetoid and stellar megastructures like Dyson's Spheres, the Death Star, V'Ger or Halo. These are epic "ships" with epic goals, that entire stories, movies or games revolve around. You might as well call Earth a ship at this point, if it had engines on it anyway.
Someone mentioned galaxy sized ships, but that seems utterly pointless to me to bother with. At this rate we might as well say out entire universe is only an atom of a projectile of a fighter from an aircraft carrier of a planet of a solar system of a galaxy of a seperate universe... It's irrelevant to anything and everything we can ever hope to relate to.
The best big ships, in my opinion, would be something like the Normandy or Hyperion, ships that carry heroes and legends with history behind them. Sure, there are larger ships out there in fiction, but they're nothing without a long service or the crew behind it.
Seeing the Enterprise D crash land, meant something. Seeing Serenity crash meant something. Hell, I'll even bet a few in here actually shed a tear when Merry from One Piece had it's funeral pyre or felt a bit of pain when the first Normandy blew up.
So size isn't everything. I've seen the Mærsk Majestic [http://en.wikipedia.org/wiki/Maersk_Triple_E_class] which is the biggest ship in the world, but even though the sheer size is breathtaking, I see no charm in it compared to the ferry I worked on for just a few weeks, where I saw the crew in all the different sections work as part of a whole.
Well, to be honest they should have removed the term "giant" from this list. I agree a lot the ships there are iconic in video gaming, but in the scheme of things they are rather small. The thing is that with current "follow the leader" gaming trends a list of truly giant ships in video games would fail to be iconic and would make most people reading it go "huh, what?" because for the most part you'd be looking for older titles or ones that are far more obscure. Admittedly in some cases you'd also be looking at things that are part of properties that were not exclusively video game based.
One ship that comes to mind purely from a video gaming series is the Harbinger from the GAME "Harbinger" which was an old space roguelike (of mixed quality) where the entire game takes place inside a giant ship that pretty much goes cruising around absorbing planets.
Then of course you have to look at the Warhammer 40k license, which has produced several games which feature massive ships. A Warhammer 40 "Battle Barge" like the "Litany Of Fury" is massive in it's own right. A "Space Hulk" which is a concept that features into several of the games is pretty much a chaos fused mass of dozens or hundreds of ships of that size citatory into a single, interconnected entity. Some Space Hulks just drift, but others can be piloted and act as the mobile headquarters of some of the nastier chaos warlords and entities out there.
Then of course we've got various "4x" type space strategy games where you might wind up constructing fleets of ships the size of the death star.
To be kind of honest the typical "big ship" in most science fiction stories winds up being pretty small in the scheme of things.
As far as some comments about the practical size of ships goes, it largely depends on the concept of space flight your using, and what the ship is intended to do. In "Yahoo" science fiction, or "space fantasy" like Star Wars, the concepts are inherently silly, and it's all about what looks cool. You have huge ships fighting at relatively close ranges. Compared to some other universes which take the actual size of space into account and have fights taking place at ranges of tens, hundreds, millions, or even billions of miles, simply put anything closer than that would simply mean that the ships would never likely run into each other to be a concern due to the sheer size of space. In such cases it typically comes down to ships being huge simply because they want to pack as much power as they can into them, you built the hugest and most powerful source of energy you can into your ship, and make the ship as big as you can to house the optimum power output. Likewise the whole idea of self sufficiency enters into it as well, a picket ship, or something travelling through a relatively "lived in" universe with waystations everywhere doesn't have to be huge. On the other hand something that's intended to be on it's own for huge amounts of time and is expected to do everything, is going to be massive. Something like a long range colony or exploration ship might basically amount to a flying city, complete with it's own factories. Also as technology and war progress projects are going to get more ambitious, especially if resources are plentiful, the idea of say a "Warmoon" sounds silly, never mind fleets of them, until you follow the bigger stick philosophy to it's logical conclusion, someone builds a big, nasty, ship, and your going to try and build one bigger. If you've got the resources to pretty much strip mine an entire planet just to build a ship.... well.
Oh and as far as someone mentioning "Earth as a Spaceship" I vaguely remember an old science fiction show called "Space 1999" if I remember, where they actually wound up using the moon as a ship. Not quite the same, but close. As I remember things an accident pretty much blew the moon out of orbit and sent it hurtling into space with the characters being stuck on a moonbase (and I vaguely remember they wound up eventually being able to steer it). A step down from that is probably planetoid-sized mobile astreroid fortresses (ie hollowing out an asteroid, building habitats inside of it, weapon emplacements on the surface, and then putting numerous engines each equal to another whole ship on it to move it...). Warhammer 40k has the Orks using those (War Roks) but the idea is much older than that, bordering on a classic. I seem to remember they had trouble dealing with one in "Andromeda" once... of course then again the main bad guy in Andromeda had a mobile artificial solar system as his personal ship.
At any rate, my point here is that when your dealing with GIANT, mind boggling, "OMG, it's blotting out the stars" ships, things like the Ishimura and Destiny's Ascension are basically space guppies, the smaller ships mentioned probably don't even register.
