A must-see. One thing to know is that the fountains operate on a schedule, so if they're not going when you happen to pass by, stick around or check back. The technology behind the fountain show is impressive, even if the fountains themselves don't wow you.
It's beautiful at night especially, with the fountains lit from below. Everyone can enjoy this and it's so frequent that while it always draws a crowd, you're still sure to get a good view without too much hassle.