Yay! Sonic Screwdriver!

 One of the coolest sci-fi tools ever, from my absolute favorite show. The Tenth Doctor's sonic screwdriver by Bruce Lowell (bruceywan), effective against just about everything, expect deadlocked seals and wood.

Oh... My... God

 I can't even begin to describe how beautiful this is. Carlyle Livingston II and Wayne Hussey spent over 800 hours putting together this Batcave. The cave itself is comprised of over 20000 individual elements, weighs over 100 lbs., and has motorized parts and its own lighting system! These men are gods to me.

17-Stage Ball Contraption

 This amazing Lego machine, built by Skiyuky, does a very simple task. Moving balls along a complete circuit. That is all it does. But it does that task in such an amazingly cool way. And it's incredibly accurate.

Rolls-Royce Engine

 The most complex Lego machine ever built, this Rolls-Royce engine is comprised of 152,455 bricks, weighs 677 lbs., and is 6.56 ft long. This engine - the Rolls-Royce Trent 1000, which powers the Boeing 787 Dreamliner - was presented on the 9th by Rolls-Royce at the Farnborough International Airshow, after having been constructed over 8 weeks by a team of 4 people.

Super Beast Castle

 This super beast castle was made by Duco Brugman (bloei). It has glowing lava! Glowing! Duco posted a video of some of the moving features of the castle.
 Click picture to enbiggen.