I'm kind of curious as to why your thread tags include "Boss & Arena, Screenshot Let's Play, Comic, and Wire/Mechanical Builds," as I've really seen none of those. Perhaps you'll add them later? I don't know, but moving on.
You have some fantastic looking builds here. It's obvious that you excel at background buildings (with front facing doors) and pixel art, as those really stand out. I'll be perfectly honest, however. I question how much work of your TEdit pixel art was brushed by your own hand, and how much was created by a third party program. They feel computer generated to me (which could be a mighty big complement if you did in fact brush them yourself in TEdit).
I would love to see up close and personal screenshots of some of the large builds that you've only posted map images of, just so I can see more of the detail (the space station and battle cruiser, for example).
I really like the smaller builds (especially the stage), and I love most of the buildings with front facing doors. The ice dungeon is extremely detailed, and looks fantastic, and I also love the fantasy tower and the tower portion of the observatory--though I have to say, the telescope portion feels like an eyesore to the rest of the build. Namely, the entire tower has a ton of fine detail to it, and the telescope feels rather lacking in that department. The angle of it also doesn't make sense (I'd recommend a 45°). Lastly, it feels quite large for the build, particularly with how far it is sticking out. I freaking love the tower it's connected to, though.
One of my absolute favorite parts of everything you've posted here, is the ore conveyor belt in the steampunk crane build. Don't get me wrong, the entire build looks great, but that conveyor build (to me) is brilliant. While I'm on the topic of your steampunk builds, I'd like to point out that I love the way you shaped the smoke coming out of the tractor. I also really like how you did the track system and hydraulic arm connected to the...shovel? Doesn't matter. I do feel the cabin of the tractor seems a bit lacking, but I can't really put my finger on the reason why, so I'll just gloss over it.
I've already taken up a bit of your time, but I do want to talk about one more thing. Your use of slime block. In some builds I absolutely love it (the cables in the space station, for example) and in some builds I absolutely hate it (the railway and research lab). To me, it is a fantastic detail tool, especially given how well it takes paint, but it only looks good in small quantities (personally). In large quantities, it gives a strange texture that really doesn't match anything else in the game (which is exactly the reason it makes for such a great accent tool). Personally, I feel like the two builds I mentioned would look fantastic if you cut back on the amount of slime and went with a different block choice (or better yet, a combination of them). It's also entirely possible that I'm not properly identifying the block choice you've made in those builds, and that it isn't slime :s haha!
All in all, great looking works here! I love your attention to detail, but I feel you can be more consistent with it (some parts feel void of detail). Also, thank you for organizing your spoilers so fantastically. It made viewing, and finding them again (for critiquing) much easier. I'm going to be blunt real fast--calling your thread "Master Build" seems highly egocentric, and it almost brought me into the thread with a negative view (really, I don't feel that either of us should use the title "Master" when it comes to our builds, if I'm being honest). Lastly, just to reiterate my opening statement, I really don't think you need to check a bunch of tags that don't really apply to thread (I don't know why that bothers me, but it does). Keep up the great work!