The power and spectacle of the falls is a must-see. The free observation points on the American side in the park allow the closest view of the Falls
I definitely would recommend everyone seeing Niagara Falls. Walk all along the falls. Go in the evening also. We watched fireworks over the falls which were fabulous. I would definitely return.
Granted, it's a plethora of activities for the kids but Niagara Falls is a national treasure of NATURE. With that said, the falls themselves are quite beautiful. If you walk all the way down to horseshoe falls (if you can get through the throngs of people), there are some excellent vistas of the falls thundering over the ridge