hexNES
Web-based NES Emulator that uses javascript and the HTML5 canvas
Discussion thread - Demo current build
Keyboard bindings:
Select: Q Start: E A: M B: N DPAD: WASD
XBOX controller bindings:
Select: Back Start: Start A: A B: X DPAD: DPAD/Left anologue
This emulator is very early in development so there will be a lot of bugs. No memory mappers are currently implemented so only NROM games are expected to boot properly. You can view a comprehensive list of games and mappers here: http://tuxnes.sourceforge.net/nesmapper.txt (Games with "---- (0)" under the mapper column are NROMs)