Space Station 13.
Too many amazing moments and memories to even count, always more to learn. I love how the open source nature of the game means there's many different servers branching off from each other, running their own custom versions of the game. Smaller servers "downstream" pick and choose which features they want to keep when the upstream servers implement something new.
Lets hope this is one of those patents that they never do anything with while simultaneously denying everyone else the opportunity to do it.
Like that 2009 Sony patent that makes you get up from your seat and yell out the name of the brand to end an ad.