Emeritus Pong is a clone of the original Pong game, trying to be relatively close to it in graphics and gameplay. The developer was quite successful at this. Huge pluses are options that allow you to play the game in 5 resolutions, two different color modes, and 3 game modes. Also, Emeritus Pong includes a very cool Pong clock.
I guess this is the best you can get with a game trying to emulate the original Pong.
Extra downloads include the Linux version and the source code.