The galaxy is a big place. The Federation alone represents a large number of alien races ... and let's pretend for a moment that many of them look nothing like humans nor speak perfect English. This presumably means that there are a lot of ship designs floating around within the Alpha Quadrant - military vessels, civilian craft, etc..

So while I can watch Star Wars and be awed by all the different kinds of ships flying over Coruscant, in Star Trek I have to be thrilled when someone decides that "the budget doesn't call for it this week" and grabs a model kit of an existing ship and sticks a few pieces of molded plastic to make a new star cruiser class. Improvisation due to necessity and lack of resources.

One of my favorite episodes is "The Tholian Web." I think the Tholians are one of the most original species that I've seen in science fiction. They're crystalline-based and have a web-like weapon which is a pretty cool concept. Their ships appear simple in design, yet somehow harbor an aggressive stance:

But I guess the third season budget was practically non-existent because some episodes later, we saw the Aurora:

I can't seem to place a finger on it, but there's something about this one which reminds me about the other. I wonder what it could be.

You also have ships which seem to have a track record of getting into trouble due to flimsy design or bad commanders. I thought the Grissom was an interesting vessel when I first saw it grace by the screen. It was sucker-punched with a single torpedo hit. Captain Esteban wasn't exactly the sharpest knife in the fleet.

These Oberth-class ships were well-recycled ... er, had a long history in the Federation. We saw the Yosemite getting stuck in a plasma streamer:

The Vico got pulled apart in the black cluster:

I have no idea why anyone would think the Pegasus was a good candidate for experimentation with bleeding-edge technology:

Hmm, could it be that influential Hollywood low-budget technique called "ship re-badging?"

Then again, sometimes re-badging wasn't even necessary. For example, the Klingon's D7 cruiser was great:

In "The Enterprise Incident," our heroes become surrounded by Romulans using familiar ships which, as reported by Spock, is due to them adopting Klingon design:

Every time I see this, I visualize someone in the studio production department counting beans thinking, "Let's just make up a story which justifies the re-use of the same ship to represent a completely different alien species."

Weak.

(BTW, the top-right corner shows the Romulan ship fading out. Result of the cloaking field? Bad special effects? You decide.)

And then there was the Jenolen:

Every. Single. Time I see this, the words, "plastic model kit parts" rush into my mind. And speaking of models, I wish I had an old USS Reliant kit so I could build it, throw some guns all over the hull, and make an episode called "Cause and Effect." I'd make millions!

Or just make a slightly-complete version of it:

Then re-use it with all the parts for another episode:

But if there's one thing that everyone knows, it's that when Klingons find a design that works, they stick to it through centuries and countless episodes and movies:

How can one not like this ship? I personally feel that "The Search for Spock" portrayed this design in the most menacingly-realistic light. It was apparently so successful that every single movie through "Generations" made use of it. This one endearing design provided an immediate, off-the-shelf villain craft solution within arms reach for the script writers. On top of that, the TV series made up at least two different classes of these, each differing apparently in size and capacity ... even though they look the same. Convenient.

So in continuing on the subject of really impressive alien ship designs, here we have a few glowing light bulbs ... I mean, a First Federation ship in "The Corbomite Manuever." Being towed by it apparently renders your ship in grayscale.

And what if you're really tight on budget this week but still need an alien spacecraft to shoot at?

Look - it's a photon torpedo! No, it's an orange orb! Screw it, let's call it an Orion scout ship! Hmm, maybe that's not original enough. Let's borrow an idea from some weight-lifting equipment:

But what if you're reeeeeeaaally hurting on the budget and can't afford to build new ships nor afford to imply there are enemy forces some distance away without showing them? You do this:

Back when I was kid, every week I was hoping this episode would come on:

It was like the Enterprise meets Jaws in space. The Doomsday Machine was a large, semi-opaque log traveling through space with a fire pit inside to barbecue planet debris. And it was huge. Really, really huge. But there's a serious scale inconsistency between the next two shots. How does someone in the effects department miss this?

Either the shuttlecraft is immensely over-sized or the USS Constellation shriveled up while under attack. Pick one, but not both.

Now there comes a time when you have to display damaged Starfleet vessels. You're naturally not going to have money to create great-looking battle scenery in variety. Recycling shots is the only option, except to us fans there's no way to do this without it being obvious. Here's the damaged Constellation in "The Doomsday Machine":

And here's the damaged Lexington in "The Ultimate Computer":

Even the starfield is exactly the same for crying out loud. But in all fairness, the budget picked up eventually and in "The Best of Both Worlds," we finally get to see a wasteland of ships as the Enterprise passes through Wolf 359:

...which suspiciously looks exactly like the shipyard layout at the surplus depot in "Unification":

Yup. Paramount's busted again. If you're going to do a debris field, do it right:

The small details count. Lots of them.