ViziCities (Demo, GitHub: robhawkes / vizicities, License: MIT) by Robin Hawkes and Peter Smart is a WebGL 3D city and data visualisation platform. It uses OpenStreetMap, and aims to overlay animated data views with 3D city layouts.
It uses Three.js, D3, Grunt, and some stalwarts like Moment.js and Underscore.js.
Thomas Palef, who has been making one HTML5 game per-week, has created a tutorial for making Flappy Bird in HTML5 and Phaser. The cool thing about the tutorial is he reduces Flappy Bird to its basic parts -- collision detection, scoring, and the player controls. Instead of worrying about whether or not the graphics are stolen from Mario, you can just follow along and learn how a game like this works.