Man, i remember getting the trial, and building the same thing over and over again, improving each time i built it,until i actually bought the whole game and finished my underground cavern.
My best memory was either on my very first creative map, when i exploded a huge canyon, and made my own nexus at the bottom, and then built a hotel on the cavern with a glass floor. the map was made i think in 1.1, not sure, it was really early on.
but i also loved when i would just go onto a DD map with my friends, and just beat the map, I think we had a record of like a half an hour to find every blue print. We would just go and play for hours, making what we thought were awesome DD servers.
Ahh, i kind of miss the old days, I think it was the simplicity of the game that i loved so much.