I created/destroyed so many new worlds just to get the materials for this, so I could get different colored dungeon blocks mostly.
One thing I didn't show off there at the end, I decided not to bore anyone further, is that I have a long line of bricks in Hell, ending with a lava pit like the one WhiteBoySlim made, and a house above so you can set your spawn point.
I also have houses at the entrance to the dungeon, corruption, and underground jungle.
I used Tedit to copy in a couple of additions you'll recognize, and also to fix a few things that I can fix with a couple of clicks rather than spending hours destroying and rebuilding. I also used a map program called TerraFirma to find some statues for the statue farm, and a few of the ones I used in the NPC housing. I may or may not have used a chest glitch to get enough wire for all my contraptions. :-X
I took some inspiration for the construction style from #5 on this list: http://www.pcgamer.com/2011/07/13/10-incredible-terraria-creations/
If you're interested in your own obsidian generator, here's how to do it: http://www.terrariaonline.com/threads/complete-1-1-obsidian-generator-automatic.66669/
I recorded everything in Bandicam, because FRAPS only lets you do 30 seconds without paying them-- Bandicam allows 10 minutes. But it appears Bandicam's compression leaves a little to be desired, so I recommend watching this in full screen and in 360p if you want to actually see the text.
And now I'm done with Terraria for a while. I definitely want to come back to it between Dec 15 and 31, for the winter content (or I might just change my clock at some point). Santa and packs of snowmen? Sign me up!