Type Specimen
A little demo site that I built when I was interviewing for a job at one point (I didn't hear back from them, go figure) but it was a little web application using javascript to demonstrate the effects of gravity and it's influence on an object dropped from every planet in our solar system (and yes, Pluto is still a planet here).
Probably not the most complex, but definitely one of the more robust projects of interactivity that I've ever tried my hand at and the more I look at it, the more I'm quite proud of the result as it genuinely feels like an educational tool for classrooms or students to discover.
You can check out the project here.