Well, I abandoned these ship designs ages ago, but they live on in my heart. I present to you:
DARK SHADOW II:

Once my best (and most expensive) ship I ever built, Dark Shadow II was the first cruiser sized ship I set out to make. While my other designs can easily beat it, I had the most fun ever with it.
THE ORIGINAL R-UPA COMMAND SHIP

Back before I named the R-UPA to what it is today, the SP took the cake. I wasn't very good with large ships (although my computer could still run the ship just fine.) Like I said, I just had fun back then, not caring about Meta or good ship designs or tournaments.
WINDOWS XP (Medium)

This was the first modded design I made on my Laptop. Whilst the mod used it outdated (I used @CaptainRedstone 's first Windows XP shields mod), it's still fun to power it up.
And that's it