Six Months of Rubicon

[Bucky]

Rubicon turns half a year old in 2 weeks, and I'd like to have some kind of highlight reel, possibly including awards. 

Possible award categories:
Most useful invention
Biggest surprise(Any type of machine)

Most innovative puzzle
Most difficult puzzle
Most fun puzzle
Best engineered puzzle

Most creative solution
Best engineered solution
Cleanest solution

The highlights collection should display a cross-section of techniques throughout the six-month period.  They should also be efficient-looking, aesthetically pleasing, or revolutionary and display a good balance of puzzles and solutions, with maybe a few other gadgets thrown in.

Input welcome

[20eight]

Great idea, Bucky.

The first puzzle that pops to my mind for innovation (it was the first one I remember that required a binary breakdown of the input) is Cleanroom (ximacad).  Also it was incredibly difficult (I, for one, spent probably eight hours on it and last I checked only about three solutions were ever posted).

Also, I would nominate MagiMaster's Passing Trains series for most fun, and the Decryption series for engineering or innovation.

[Bucky]

Here are a few nominations, found using the search engine
The first puzzle in the warehouse has to go in the highlights: gobudif
(Difficult, Highlights)Here's an early example of a very challenging puzzle: gekixin
(Innovative)The first puzzle to require analyzing a ? crate in order to match it:[level]detyxac[/level

Magimaster's "Passing Trains" should be included in highlights as the first "serial" puzzle.