Gorgeous!!
I live in Vegas, and I work on the strip. So I've probably seen the fountains go off 2 dozen times, if not more. But it never gets old. The fountain show is massive, and so gorgeous whether you're watching it day or night.
It's just spectacular. If you visit Vegas this is a MUST SEE!!!! Don't miss the Bellagio fountains it's one of the more beautiful things on the strip.