Before it invariably gets taken offline, you might want to check out a remake of the original Legend of Zelda. It's not just a straight port of the original, though. Its pixel art assets were remade in voxels, which are rendered in WebGL at an angle that's similar to what the original pixel art implies. Original NES controls are overlaid on the screen, which is useful for multi-touch, but keyboard also works.
Most of the game is plugin-free and running in the browser. The only thing that requires plug-in support is audio, and it doesn't play nice with click-to-activate. It would have been nice for them to implement it in WebAudio API, and implement Gamepad API while they're at it, but who am I to criticize a passion project that will likely be challenged by Nintendo in a handful of days?
I'm not sure how complete the game is. They seem to imply that all eight dungeons are available, but I haven't had a chance to check.