The best way to experience the Fountains of Bellagio is from one of their luxurious suites IN the Bellagio from your king-size bed while the water is dancing to the music streaming throughout your room. The Fountains are active until about midnight everyday and are absolutely beautiful to see. And so relaxing...
And while you can stroll by and enjoy the lights and water displays from the street, I highly recommend treating yourself and experiencing this from the inside. Trust me. :)